CD274 and breast carcinoma: Moreover, in a panel of breast cancer cell lines, the level of RBMS1 was notably elevated in TNBC cells (e.g. MDA-MB-231 and HCC1937) as compared to normal breast cells and other subtype breast cancer cells (Figs. S1E and S7), indicating that RBMS1 might regulate the PD-L1 checkpoint immune surveillance in TNBC.