TRIM28 and cancer: The expression of PD-L1 in tumor cells is crucial for their escape from antitumor immunity.8 The regulation of PD-L1 expression has been broadly studied at different levels, including transcriptional, translational, and post-translational levels, in distinct cancer types.5–8,36 It has been observed that multiple post-translational modifications, such as glycosylation, ubiquitination, phosphorylation, palmitoylation, and acetylation regulate the expression and functions of PD-L1.37 Herein, we demonstrated that TRIM28 positively regulates the mRNA and protein levels of PD-L1.