CD274 and cancer: For example, it was found that exposure of cancer cells to physical DNA damaging factors including ionizing radiation [85,86] and chemical factors that induce DNA damage such as topoisomerase inhibitors (camptothecin [87], doxorubicin [88,89,90], and irinotecan [91]), alkylating agents (carboplatin [92,93], cisplatin [94,95,96,97,98], oxaliplatin [99], and mitomycin C [100]), or antimetabolites such as decitabine [101,102,103] and 5-fluorouracil (5-FU) [104,105,106] can lead to up-regulation of PD-L1 expression in the treated cells.