It has been confirmed that PAX4 is a key diabetes mellitus (DM) susceptibility gene, for single-nucleotide polymorphisms (SNPs) and mutations in PAX4 caused maturity onset diabetes of the young 9 (MODY9) (Anık et al. 2015), increased susceptibility to type 2 diabetes mellitus (T2DM) (Sujjitjoon et al. 2016a), and were also associated with type 1 diabetes mellitus (T1DM) (Biason-Lauber et al. 2005) and ketosis prone diabetes (Mauvais-Jarvis et al. 2004). The gene discussed is PAX4; the disease is type 2 diabetes mellitus.