Using the NOD model, RNAi has already provided valuable insight into how expression of the T1D candidate genes IL17 (88), PTPN22 (89), CTLA4 (90), CLEC16A (91), RGS1 (92), and Slc11a1 (Nramp1) (93) contribute to diabetes development. The gene discussed is CTLA4; the disease is type 1 diabetes mellitus.