LEP and obesity due to melanocortin 4 receptor deficiency: Therefore, in the obesity-related cancer environment where many cytokines show altered profiles, angiogenesis factors (i.e., EGF, VEGF, and PAI-1) and inflammatory mediators (i.e., IL-1, IL-6, TNF-α, and leptin) are thought to cultivate a favorable environment for neoplastic cell growth.