CD274 and cancer: Resistance to chemotherapeutic agents, such as paclitaxel, etoposide, and 5-fluorouracil, has been linked to pathways regulating PD-L1 expression, including JAK/STAT, MAPK, PI3K-AKT, and NF-κB in cancer cells, including human BC (Doi et al. 2017; Zhang et al. 2008).