This was interpreted to indicate that the beta cell failure of type 2 diabetes, i.e., the inability of the cells to respond to glucose with appropriately increased insulin secretion also would apply to the incretin hormones [in agreement with the demonstration by Perley and Kipnis (7) and Nauck et al. (59) of the loss of incretin effects in type 2 diabetes]. The gene discussed is GCG; the disease is type 2 diabetes mellitus.