CXCL9 and neoplasm: Moreover, the response rates to the immune checkpoint blockade (ICB); anti-PD-1/anti-CTLA-4 in breast cancer was found to have a direct correlation with the extent of tumor immune infiltrate, which is correlated with upregulated macrophages derived CXCR3 ligands, CXCL9, and CXCL10 (38).