INS and obesity due to melanocortin 4 receptor deficiency: In this study, 42 genetic loci were found to be significantly associated with the T2D risk, including missense variants in SULT1C4, FGA, and TAS2R38, and UTR variants in HLA-G and HTR1B. These genes are involved in pathways regulating glucose homeostasis, insulin signaling, obesity, inflammation, and stress response.