The high proportions of CD8+ TILs—denoted in the TNBC patient biopsies prior to chemotherapy (Figure 1) and in 4T1 tumors not treated by chemotherapy (Figure 2)—suggest that chemotherapy selected for existing CD8+ TNFR2+ TILs or promoted their proliferation at the tumor site. The gene discussed is TNFRSF1B; the disease is neoplasm.