Explore the vast range of titles available.

It is a short step from understanding that health is a product of the forces around us-of the conditions of where we live, work, and play-to a call to generate social policy that changes conditions that create health in populations. Social policies can, by design, change elements ofthe world around us, ranging, for example, from taxation policies that can provide resources to governments to invest in better parks and opportunities for recreation to policies that alter transportation routes or make health care resources available to more people. It is therefore reasonable that public health increasingly sees the implementation of healthy social policy as part of its goal, consistent with the aspirations of a muscular public health. There are two principal barriers to the consistent implementation of healthy social policy. The first is political. Policymaking definitionally involves the shifting of resources. Taxation, for example, takes money from individuals, sectors, or groups and allocates it to funding public goods. The implementation of particular health programs must involve the commitment of assets that could have been used for other purposes, which groups who do not benefit from the programs would perhaps prefer. Therefore, the implementation of social policy for health must navigate these political challenges and be seen by the public and policymakers alike as a priority for action and investment of public funds. It is with this in mind that we have often advocated public health tellingthe storyofhealth2asa meansofmakingthe case for the importance of particular policies to elevate their visibility and importance amid other potential policiesthatdo not have health attheircore.

Common germline variants of the APOE gene are major risk modifiers of neurodegenerative and atherosclerotic diseases 1 – 3 , but their effect on cancer outcome is poorly defined. Here we report that, in a reversal of their effect on Alzheimer’s disease, the APOE4 and APOE2 variants confer favorable and poor outcomes in melanoma, respectively. Mice expressing the human APOE4 allele exhibited reduced melanoma progression and metastasis relative to APOE2 mice. APOE4 mice exhibited enhanced anti-tumor immune activation relative to APOE2 mice, and T cell depletion experiments showed that the effect of APOE genotype on melanoma progression was mediated by altered anti-tumor immunity. Consistently, patients with melanoma carrying the APOE4 variant experienced improved survival in comparison to carriers of APOE2 . Notably, APOE4 mice also showed improved outcomes under PD1 immune checkpoint blockade relative to APOE2 mice, and patients carrying APOE4 experienced improved anti-PD1 immunotherapy survival after progression on frontline regimens. Finally, enhancing APOE expression via pharmacologic activation of liver X receptors, previously shown to boost anti-tumor immunity 4 , exhibited therapeutic efficacy in APOE4 mice but not in APOE2 mice. These findings demonstrate that pre-existing hereditary genetics can impact progression and survival outcomes of a future malignancy and warrant prospective investigation of APOE genotype as a biomarker for melanoma outcome and therapeutic response. Heritable APOE variants in patients with melanoma influence anti-tumor immunity and modulate metastatic progression and response to immunotherapy.

Four years ago, in January 2016, we launched a section in AJPH called \"A Public Health of Consequence.\"1 In that inaugural section, we suggested, \"The role of scholarship in public health should therefore be to generate the knowledge that can inform public health action aiming to improve the conditions that makes us all healthy. \"1(p10) And we asked, \"But does our scholarship today do that?\" We aimed to highlight a few articles each month, asking, \"Why do these articles matter?\" Our goal, as we set it for ourselves then, was threefold: First we aimed to make salient the questions: does particular work matter, and how can we make sure that it is presented in a way that influences the work of improving public health. Second, we hoped \"to develop a more robust intellectual architecture that informs how we think about the very idea of a public health of consequence. \"1(p11) Third, we aimed to generate discussion and disagreement, seeing discussion as a productive force in science. Today, four years later, we bring the section to a close-for reasons we discuss in conclusion-and as we do so, we ask ourselves, how well did we do toward meeting our goals?

Public health practice builds on what we know from the population health sciences to improve health and reduce or eliminate disease. There are abundant rewards in population health science and public health practice, but the privilege of being part of an enterprise that aspires to generate good health for millions of people-whole populations-must be one of the most compelling aspects of the work. We create the evidence base that can change and inform policy-policy that creates changes that affect many. Creating opportunities for exercise will provide that opportunity for whole cities; changing the age at which cigarettes can be purchased means that a whole generation of future adults will smoke less, improving the health of whole countries. Striving for evidence-based policies informs many of the decisions we make in our science and practice. It pushes us to think about what matters most, for example, focusing on ubiquitous forces that influence the health of many in populations and communicating the importance of population health science to change the public conversation. And yet, the goal of making population health improvement central to our mission is balanced by other principles that also should inform the work of public health. Central to these is a concern with social justice. In many ways social justice is at the heart of the work of public health. Health is socially patterned and population health is interlinked, influenced by shared circumstances, by transmission of behaviors and of pathogens, suggesting that the health of one is inextricable from the health of all. Therefore, we simply cannot do our work in public health without paying attention to the underlying structures that shape that health and the principles of social and economic justice that structure a world that affects the health of all. This concern with the foundational principles of public health has implications for, and brings nuance to, what might otherwise be a utilitarian approach to public health-the promotion of the health of as many as possible over and above all other considerations.

[...]our reluctance to use the word \"cause\" has come from the conflation of the act of causal thinking and the application of statistical methods to observed data that collectively have come to be called \"causal modeling\" approaches. When multilevel modeling emerged as a common useful technique in population health science more than 15 years ago, its widespread adoption also came in some respects at the expense of multilevel thinking.6 The adoption of statistical approaches that are new and unfamiliar may, reasonably enough, occasion anxiety, perhaps fueled by the relatively small number of scholars who, at first, are familiar and comfortable with the relevant methods. [...]the reluctance to use the word \"cause\" represents the long tail diffusion of the science and the attendant loss ofnuance that is well accepted among leading thinkers in the field as methods and approaches are adopted by the broader mass of scientists and practitioners.

The statement \"Vision without execution is hallucination\" is generally attributed to Thomas Edison and is a modification of an ancient Chinese proverb; it has gained currency in the private sector as a motivational, agenda-setting aphorism. The idea of this statement is that although vision is important and can set our sights, little is achieved without the hard work necessary, the step-by-step progress, toward achieving the vision. Although this may seem inarguable, it has often struck us in our professional experience how often the dots fail to be connected, how often vision is articulated without tactics rather than implemented to concretely move organizations toward that same vision. Indeed, serial expressions of vision and priorities without action create an environment of hopelessness rather than empowerment. This is a nagging preoccupation in some of our writing about a public health of consequence, featured regularly in AJPH since 20161 and referred to by McBride et al. in their article \"Public Health of Consequence: Shifting the Cultural Narrative From Churning Grants to a Scholarship of Consequence\".

We are writing this editorial just days after mass shootings in Dayton, Ohio, and El Paso, Texas, resulted in 31 people dead and more than 50 people injured. The US national conversation has been, over the past 48 hours, ablaze with commentary about the need for policy efforts that reduce the consequences of gun violence. And guns have come, once again, to dominate the political conversation. In some ways this cycle is familiar. Although firearm mortality in the United States has been roughly at the same level for nearly 20 years (although there has been an increase in the past couple of years), attention to the issue has crystallized around mass shootings, particularly since the Newtown, Connecticut, shootings in 2012 when 26 students were killed at Sandy Hook Elementary School. The Parkland, Florida, shooting in 2018, when 17 students were killed at Marjory Stoneman Douglas High School, catapulted a new generation of student-led activism to the fore, making gun violence part of the ongoing national conversation. Although mass shootings account for fewer than 2% of all the gun-related fatalities in the United States, they have served to focus public attention in a way that the more than 36 000 annual deaths from firearms, most from suicide, have not. In their response to gun violence, public health practice and academic public health have lagged substantially behind in their study of one of the defining epidemics of our time. Public health practice has been hampered in no small part by political forces. The Dickey Amendment, attached to an omnibus spending bill in 1996, prohibited the Centers for Disease Control and Prevention (CDC) from spending money \"to advocate or promote gun control.\" This amendment had a chilling effect in multiple ways, but in particular it served notice to public health practice not to engage in work that aimed to limit access to or availability of guns. Public health agencies at the municipal, state, and federal levels were all appropriately concerned with taking on an issue that could result in substantial political opposition and potentially a cut in funding to other areas of work. This climate of hesitation to take on issues related to firearms spread to research funding, with neither the CDC nor the National Institutes of Health (NIH) making substantial funds available for research for approximately two decades. A direct result of this was a dramatically lower research engagement with firearms and their consequences than would have been commensurate with the scope of morbidity and mortality that accompany guns in the United States.

THERE IS A LAG IN CRISIS RECOGNITION The number offirearm deaths in the United States was largely unchanged for about 17 years. [...]insofar as the 34 000 or so annual deaths from firearms are alarming to the public consciousness, they have been so for nearly two decades. KNOWLEDGE IS POWER Congressman Jay Dickey, who sponsored the amendment to an omnibus spending bill in 1996 that is broadly credited with having a profound influence on firearm research (see Rostron, p. 865) regretted his decision before he died,5 recognizing that, absent data about the firearm epidemic, we were consigned to generate collective heat about the issue, but little light. POPULATION HEALTH EMERGES FROM COMPLEX SYSTEMS Populations are complex systems, characterized by multiple heterogeneous actors, interacting often randomly, with feedbacks loops and nonlinearities.6 This has been borne out clearly in the firearm discussion.