The intervening years have also seen progress in the understanding of single molecular abnormalities in breast cancer related to specific molecular therapies, such as BReast CAncer (BRCA) gene, programmed cell death-1 ligand (PD-L1), phosphatidylinositol 3-kinase (PI3K), or estrogen receptor 1 (ESR1). The gene discussed is CD274; the disease is breast carcinoma.