GCG and cancer: SigmaR1 is overexpressed in cancer samples from colorectal cancer (CRC) patients, is associated with higher tumor grade and promotes tumor invasion and angiogenesis (47, 48).PYGM plays a role in insulin and glucagon signaling as well as insulin resistance pathways involved in the regulation of glycogen levels, and its expression level is closely associated with survival prognosis in many cancers (49, 50).