CD274 and breast cancer: Light microscopy observations suggested that RSV induced a hypertrophy-like phenotype in treated JIMT-1 and MDA-MB-231 cells (Figure 6, top panels), a second PD-L1-overexpressing breast cancer model representative of the basal-like subtype [40, 67, 68] as indicated by the transformation of spindle-shaped control cells to more enlarged, irregular, and flattened cell morphologies after switching to culture medium with RSV (Figure 6, top panels).