INS and obesity due to melanocortin 4 receptor deficiency: Its inhibition results in less methylation of developmental-related gene promoters in the CpG islands, such as FOXP3 (regulatory T-cell master transcription factor), insulin (INS), insulin-linked growth factor 1 (IGF-1), or fat mass- and obesity-associated gene (FTO), and, consequently, greater expression of the latter [123,131,132].