PTPA and hepatocellular carcinoma: Following their observation that CIP2A is involved in mediating the apoptotic effect of bortezomib in hepatocellular carcinoma, Yu et al., also reported a proteasome-independent mechanism by which bortezomib induces autophagy in hepatocellular carcinoma through the CIP2A-PP2A-AKT-4EBP1 pathway [107].