In addition to its oncogenic effect, we observed a correlation between high CBX1 expression and an impaired anti‐PD‐1 response, and found that CBX1 could inhibit the NPC‐cell killing by chimeric antigen receptor (CAR)‐T cells in vitro through PD‐L1 upregulation mediated by IFN‐γ‐STAT1 signaling. The gene discussed is CD274; the disease is nasopharyngeal carcinoma.