In particular, high-frequency PD-1−TIGIT + CD8+ tumor-infiltrating lymphocytes (TILs) were observed in TNBC cells, making the strategy of dual PD-1/TIGIT blockade a promising therapeutic approach via increasing CD8+ TIL function in TNBC, which may further improve the immunotherapy for breast cancer [103]. Here, PDCD1 is linked to breast carcinoma.