PKM and hepatocellular carcinoma: Importantly, phosphorylation of purified His-PKM2 by recombinant active JNK1 paralleled an increase in PK activity in a dose-dependent manner (Fig. 8e), which is consistent with the enhanced activity of PKM2 in PARP14-depleted HCC and JNK1CA-transfected HEK293T cells (see Fig. 4a and Fig. 7a).