Indeed, knocking out UBC9 or treating cancer cells with 2-D08 and ML-792 significantly enhanced the apoptosis induced by etoposide (Fig. 6b–d); more importantly, the combination of etoposide with 2-D08 sensitized tumor cells to etoposide in vivo (Fig. 6e–g). The gene discussed is UBE2I; the disease is cancer.