In summary, we found that targeting BRD4 suppressed radiation‐induced and cisplatin‐induced PD‐L1 up‐regulation through disrupting the recruitment of IRF1 to PD‐L1 promoter and enhance the anti‐tumour immunity of chemoradiation in a CD8+ T cell‐dependent manner in NSCLC without significantly increased treatment‐related toxicities. The gene discussed is IRF1; the disease is neoplasm.