CD274 and neoplasm: Additionally, the elevated level of PD‐L1 by pFLAG‐FOXM1 overexpression, which mimics the situation in a malignant tumor mass, was significantly reduced to 52.6% in H1299 cells (p < 0.05) and 59.2% (p < 0.01) in PC9 cells by siRNA, and by 41.9% in H1299 cells (p < 0.01) and 68.0% in PC9 cells (p < 0.05) by TST treatment.