PDCD1 and triple-negative breast carcinoma: The use of anti-PD1 pembrolizumab in combination with chemotherapy (nab-paclitaxel, paclitaxel, or gemcitabine–carboplatin) for first-line metastatic triple-negative breast cancer (TNBC) and for patients diagnosed with high-risk early-stage TNBC (anthracyclines plus cyclophosphamide followed by paclitaxel plus carboplatin) as a neoadjuvant treatment and then continued as an adjuvant treatment after surgery was approved in 2020 [1].