PKM2 is the major isoform in HepG2 cells. Immunoblot showing that PKM2 expression is many-fold higher than other PK isoforms in hepatoma cells. PKL, which is typically present in normal liver cells, is expressed at very low levels in cancerous HepG2 cell line. M1, which is present in energy requiring tissues such as brain and muscle, is completely absent in HepG2 cells. L6 cell line (rat skeletal muscle) is used as a positive control for M1 and a negative control for PKL isoform.