Inhibition of CXCR4 with AMD3100 decreases desmoplasia, reduces immunosuppression, and improves T cell infiltration and response to ICIs in breast cancer (138) while targeting PD-1 and CXCR4 potentiates anti PD-1 efficacy in murine immune sensitive and immune resistant tumors (139). This evidence concerns the gene PDCD1 and breast cancer.