LEP and obesity due to melanocortin 4 receptor deficiency: However, several obesity-related changes have been shown to influence carcinogenesis, including hyperinsulinemia, elevated leptin levels, chronic inflammation, oxidative stress, HIF-1α activation, cytokine secretion, DNA methylation, visceral adipose dysfunction, release of adiponectin, exosome miRNA release, and changes in the metabolism of sex hormones74.