GCG and diabetes mellitus: The pathological significance of the blockade of CXXC5‐Dvl PPI was indicated by the high overexpression of CXXC5 in obese patients with diabetes and its inverse correlation with the major metabolic genes directly subjected to regulation by Wnt/β‐catenin signalling, such as GLP1, TCL7L2, WISP1, c‐MYC, CCND1, and PPARδ .27, 30, 31