PTPA and Hypoglycemia: At the same time, hypoglycemia upregulates B56δ, the PP2A regulatory subunit, resulting in the formation of a PP2A-B56δ active complex with a high affinity toward GSK3β to specifically activate the PP2A-GSK3β axis, leading to a decline in the pro-survival protein MCL-1, thereby interfering with glycolysis in hepatocellular carcinoma cells (81).