INS and type 2 diabetes mellitus: The genetic variants related to T2DM in Caucasians are mainly related to insulin resistance [32], but those in Asians, including Chinese, Japanese, and Koreans, are involved in insulin secretion (GLP1R, PAX4, HNF4A, SLC30A8, HHEX, CDKAL1, CDKN2A/B, and GCKR) [33,34,35,36].