Importantly, the adipocyte-macrophage crosstalk in obesity-related BC mainly involves excessive inflammatory cytokines secretion (TNF-α, IL-1β, IL-6, and PGE2), TSC1-TSC2 complex-mTOR, insulin resistance, endoplasmic reticulum stress, and increased levels of aromatase activity and estrogen production. Here, CYP19A1 is linked to obesity due to melanocortin 4 receptor deficiency.