Post prandial C-peptide was non-significantly higher with DPP-4 inhibitors vs. placebo in the subgroup analysis according to diabetes duration: MD = 19.91 [−11.97, 51.79], p = 0.22 in diabetics < 1 year vs. MD = 279.89 [−7.78, 567.57], p = 0.06 for diabetics since 1 to 3 years ago (S2 Appendix). The gene discussed is DPP4; the disease is diabetes mellitus.