TRIM21 and neoplasm: Notably, the impact of TRIM21 on tumor immunity also exhibits a dual nature, as it can either promote or inhibit antitumor immune responses by directly binding to and destabilizing its substrates (Du et al, 2023; Fu et al, 2023; Li et al, 2023; Shi et al, 2022), including PD-L1 (Gao et al, 2021; Sun et al, 2023).