For instance, an upregulation of CD4 and CD8-positive T cells is related to the favorable prognosis in triple-negative breast cancer (TNBC) (7), while the presence of CD25high effector regulatory T cells hampers responses to programmed cell death protein 1 (PD-1) blockade in TNBC (8). The gene discussed is PDCD1; the disease is triple-negative breast carcinoma.