PD-1 overexpression was also oberved in the triple-negative breast cancer (TNBC) subtype and could be as a predictor for TNBC subtype in both TCGA (AUC = 0.671) and METABRIC (AUC = 0.672) databases (Figures 3A–D). The gene discussed is PDCD1; the disease is triple-negative breast carcinoma.