PKM and hepatocellular carcinoma: Duble mutant P53 (N340Q/L344R) accerlerates the growth of hepatocellular carcinoma cells by activated telomerase and prolonged telomere through the cascade of P53 (N340Q/L344R)-CUDR-PKM2-pH3T11−(H3K9me1-HP1α)-Pim1−(TERT− HOTAIR- TERRA).