Soon after the discovery of this glucoregulatory mechanism, several potent low molecular weight competitive DPP-IV inhibitors (gliptins, gli- “antihyperglycemic” + (pe)pt(idase) + in(hibitor), Table 2) were introduced into clinical practice for the treatment of type 2 diabetes mellitus (see [2] for review). The gene discussed is DPP4; the disease is diabetes mellitus.