As shown in Fig. 4d, e, in comparison with the negative control PBS or NPControl, NPTyr-CXCL9 or NPTyr-αPD-L1 that expressed CXCL9 or αPD-L1 alone in melanoma significantly inhibited the growth of melanoma, achieving 59.0% or 69.5% tumor growth inhibition rates. Here, CXCL9 is linked to melanoma.