Given that Black women also tend to have higher age-adjusted prevalence rates of obesity (approximately 57% among non-Hispanic Black vs. 40% among non-Hispanic White women [4]), we hypothesize that inter-individual variation in adiposity and adiposity-related biomarkers (namely leptin [LEP], leptin receptor [LEPR], adiponectin [ADIPOQ], adiponectin receptor 1 [ADIPOR1], and adiponectin receptor 2 [ADIPOR2]) within the breast tumor microenvironment might be involved in the observed racial differences in aggressive breast cancer phenotypes between Black and White women. The gene discussed is LEPR; the disease is obesity due to melanocortin 4 receptor deficiency.