Gain-of-function mutations and common variants in the human genes encoding the pore-forming (KCNJ11) and regulatory (ABCC8) subunits of the KATP channel have been implicated in neonatal diabetes (ND), early-onset diabetes, and an increased risk of developing type 2 diabetes later in life (Hattersley and Ashcroft, 2005; Pipatpolkai et al., 2020). Here, KCNJ11 is linked to type 2 diabetes mellitus.