USP39 and hepatocellular carcinoma: By applying the Tet-On system to replenish KANK2 expression upon doxycycline induction, we found that restoration of KANK2 partially reversed the adverse effects of USP39 knockdown on HCC cell proliferation and cell cycle control (Figs. 5G, S9B, D, F), underscoring the importance of USP39-regulated KANK2 splicing in hepatocarcinogenesis.