GCG and cancer: Notably, eight KEGG terms, including ‘fructose and mannose metabolism’, ‘central carbon metabolism in cancer’, ‘glucagon signaling pathway’, ‘steroid biosynthesis’, ‘legionellosis’, ‘insulin resistance’, ‘glycolysis/gluconeogenesis’, and ‘protein processing in endoplasmic reticulum’, were significantly enriched using a threshold value (Padj < 0.001) (Figure 4a).