DPP4 and Other metabolic disease: With regard to individual functions in “Lipid Metabolism”, “lipid synthesis” was found to be the most significant (P = 5.76E-06) and repressed (activation Z score = −2.02) function, which consisted of ACOX2, AKR1B1, DHCR24, DPP4, FABP3, FADS2, FDFT1, ITGA6, PLIN2, PON2, PTGS1, TRPV2, most of which have been previously reported to be associated with metabolic disease, as discussed later (Table 2) [14-23].