In addition to hormone receptors and human epidermal growth factor 2 (HER2), the immunohistochemical detection of programmed cell death ligand 1 (PD-L1) in advanced triple-negative breast cancer and the detection of mutations in the breast cancer 1 (BRCA1) or BRCA2 gene in the patient’s germline and mutations in the phosphatidylinositol 3 kinase (PI3K) pathway are currently relevant when making decisions regarding targeted therapy. The gene discussed is CD274; the disease is triple-negative breast carcinoma.