In a recent study, HDACi Romidepsin was found to upregulate PD-L1 expression and the combined application of Romidepsin and anti-PD-1 antibody could enhance the antitumor therapeutic effect and partially reverse the influence of Romidepsin on CD4+ and CD8+ T cells in colon cancer (111). Here, CD274 is linked to malignant colon neoplasm.