NEUROD1 and type 2 diabetes mellitus: Mutations in the NEUROD1 gene in humans are linked to type 2 diabetes (Malecki et al., 1999) and a subtype of maturity-onset diabetes of the young (MODY6) (Malecki et al., 1999; Rubio-Cabezas et al., 2010; Horikawa and Enya, 2019).