With a focus on cell-type-specific type 2 diabetes risk genes, we identified 32 genes (Fig. 2b): seven for alpha cells (Arg1, Cpq, Etv1, Foxp1, Ociad2, Scgn and Sumo2); ten for delta cells (Ache, Cntnap2, Ehf, Epb41l4b, Fxyd2, Hhex, Pcsk1, Polr1d, Tcf4 and Trim9); none for gamma cells; and 14 for macrophages (Anxa5, Apoe, Ccnd3, Cd68, Chmp4b, Fcgrt, Gadd45g, Hpgd, Ifitm3, Ly86, Samhd1, Sell, Treml2, Zfhx3). The gene discussed is TCF4; the disease is type 2 diabetes mellitus.