Studies have shown that the intratumoral abundance of CXCL9, 10 or 11 determines the numbers of tumor-infiltrating T cells, whereas most tumors restrain the expression of CXCL9, 10 or 11 to reduce T-cell recruitment, leading to the frequent failure of PD-1/PD-L1 blockade therapy21,22. Here, CXCL9 is linked to neoplasm.