GCG and type 2 diabetes mellitus: Thus, the amino acid peptide sequence of GLP‐1 was first discovered by Habener and colleagues in the early 1980s through decoding of recombinant cDNA clones in anglerfish (Lund et al., 1982) and subsequently found to enhance insulin secretion in the perfused rat pancreas (Mojsov et al., 1987), with clinical approval of GLP‐1 mimetic for the treatment of type 2 diabetes mellitus (T2DM) following in 2005 (Kolterman et al., 2005).