Even in donors younger than 40 years with T2D, increased IGF1R positivity (IGF1R+) in β-cells is associated with higher expression levels of p16Ink4a mRNA levels and increased senescence-associated β-galactosidase (SA-βGal) activity, consistent with them being senescent. The gene discussed is CDKN2A; the disease is type 2 diabetes mellitus.