CD274 and cancer: Lac was also found to inhibit IFN-γ-induced PD-L1 expression in other human melanoma cells (M14, A2058, and MeWo) and lung cancer cells (A549 and PC-14) (Fig. 1D), suggesting that Lac shows its inhibitory effect on IFN-γ-induced PD-L1 expression regardless of cancer cell type.