In addition, after intravenously injecting NPSur-C9AP into mice bearing B16-F10 melanoma, the intratumoral concentrations of CXCL9 and αPD-L1 proteins were significantly increased to 11.76 and 55.65 ng g−1; by contrast, the expression of CXCL9 and αPD-L1 proteins was only moderately upregulated in liver and spleen and was not increased in heart, lung and kidney (Fig. 8c, d). This evidence concerns the gene CXCL9 and melanoma.