CD274 and breast cancer: For instance, a low concentration of cisplatin (CDDP) has been shown to upregulate PD‐L1 expression in mouse hepatoma H22 cells, whereas paclitaxel, etoposide and 5‐fluorouracil could induce PD‐L1 expression in human breast cancer cells (Qin et al., 2010; Zhang et al., 2008).