PIASy mediates SUMOylation of IKKγ at Lys 277 and 309 by SUMO1, which is required for NF‐κB activation in response to genotoxic agents.[117] However, PIAS4 promotes tumorigenicity and metastasis of HCC cells by promoting the SUMOylation of AMPKα and IKKγ. Here, PIAS4 is linked to hepatocellular carcinoma.