TRIM21 and hepatocellular carcinoma: Furthermore, one target of the E3 ubiquitin ligase activity of TRIM21/Ro52 is p62, and the function of the downstream p62–Keap1–Nrf2 antioxidant pathway in HCC is also controversial; again, the expression of TRIM21/Ro52 has been shown to both involve in promoting and suppressing HCC progression [55, 56].