TET2 and hepatocellular carcinoma: Intriguingly, deficiency of TET2 sensitizes cell to sorafenib with dramatically decreased cell viability and elevated cleaved PARP, which is a biomarker of cell apoptosis [36] (Fig. 1A, B), whereas lenvatinib and regorafenib fail to exert similar effect in TET2 knockout (hereafter sgTET2) HCC cells (Supplementary Fig. S1B–E).