For instance, combination of PLGA nanoparticles coencapsulating the poorly immunogenic melanoma antigen, tyrosinase-related protein 2 (TRP2), along with Toll-like receptor 4 ligand (TLR4) (7-acyl lipid A) led to a therapeutic antitumor effect against melanoma after the subcutaneous administration to mice [151]. This evidence concerns the gene TLR4 and melanoma.