As shown in Figure 2, under the treatment with MLN8237, the up-regulation of PD-L1 mRNA levels in breast cancer SKBR3 and MDA-MB-231 cells exhibited a dose- and a time-dependent manner (Figures 2A–C), respectively, consistent with the western blot and flow cytometry results (Figures 2D–F). Here, CD274 is linked to breast cancer.