PPARGC1A and neoplasm: As PPARα and its upstream cofactor PGC-1α were increased in hypoxic Hepa-c4 cells, and since both proteins have been linked to peroxisomal function and are major regulators of liver lipid metabolism and gluconeogenesis [58,59,60] (n.b. Hepa-1 cells are hepatoma cells, originally derived from hepatocytes), it is likely that PPARα and PGC-1α play important roles in the metabolic reprogramming of the Hepa-c4 cells and of tumours in general.