CD69 and melanoma: Owing to the synergy of CXCL9 and αPD-L1, the number of CD69-positive CD8+ T cells in NPTyr-C9AP-treated melanoma reached 2.33 × 105 cells per gram tumor, which was 5.1- and 2.1-fold that in the NPTyr-CXCL9 and NPTyr-αPD-L1 groups, respectively (Fig. 5e).