Wang et al. demonstrated in melanoma mice that TLR7 agonists loaded into mesoporous polydopamine (MPDA) nanocarriers could directly target DCs in the TDLN, promote DC maturation and antigen-presenting ability, facilitate T cell activation and migration, and significantly enhance anti-PD-1 efficacy and reverse melanoma resistance in mice[195]. Here, PDCD1 is linked to melanoma.