Meanwhile, the CaV1.2 and CaV1.3 mRNA levels were elevated by overexpressing CaVγ4 in non-diabetic human islets (p = 0.005 and 0.039, respectively; Fig. 4c), as well as in T2D human islets (Supplementary Fig. 4a). The gene discussed is CACNA1D; the disease is type 2 diabetes mellitus.