OTUD4 and hepatocellular carcinoma: To determine the effects of OTUs in HCC metastasis, we generated MHCC‐LM3 HCC cells with stable knockdown of each OTU member including OTUB1, OTUB2, OTUD2, OTUD3, OTUD4, OTUD5, OTUD6B, OTUD7B, and OTULIN.