CD274 and ovarian cancer: For instance, an increase in PD-L1 has been described in breast cancer cells after treatment with paclitaxel, etoposide, 5-fluorouracil (5-FU) [15], and irinotecan [16]; gemcitabine or paclitaxel resulted in enhanced expression of PD-L1 in ovarian cancer cell lines in an NF-kB-dependent manner [17], while carboplatin plus paclitaxel or 5-FU plus cisplatin led to an increase of PD-L1 expression in esophageal squamous cell carcinoma [18].