BRD4 and non-small cell lung carcinoma: Targeting BRD4 decreased treatment feedback PD‐L1 up‐regulation via blocking the recruitment of IRF1 to PD‐L1 promoter and sensitized NSCLC cells to chemoradiotherapy and anti‐PD‐1 antibody through a cytotoxic T cell‐dependent manner without increasing toxicities.