Abdulkarim et al. (28) reported that after the R658C mutation in the PPP1R15B gene in two children, a conserved amino acid in the binding region of protein phosphatase-1 was affected, reducing PPP1R15B dephosphorylation and leading to β-cell apoptosis, small head disease, short stature, intellectual disability, and diabetes. Here, PPP1R15B is linked to diabetes mellitus.