First, pembrolizumab—the highly selective monoclonal-antibody-based therapy against PD-1—was the first shown to be successful as a monotherapy for metastatic triple-negative cases of breast cancer (TNBC), with some long-lasting responses reported, and has also shown benefit for advanced ER+/Her2-in the KEYNOTE trials (66–70). The gene discussed is ERBB2; the disease is breast cancer.