CXCL9 and melanoma: In addition, the numbers of CD69-positive CD8+ T cells in melanoma of NPTyr-αPD-L1, NPTyr-CXCL9 & anti-PD-L1 or NPTyr-C9AP groups respectively reached 3.71, 6.34 or 7.56 × 105 cells per gram tumor, which was 1.3-, 2.2- and 2.6- fold of that in the anti-PD-L1 group (Fig. 6f, Supplementary Fig. 24a).