Insufficient T cell trafficking into the tumor sites, especially in solid tumors, reduces the therapeutic efficacy of immune checkpoint blockades.39 In the present study, we demonstrated that Lsp1 KO T cells more effectively suppressed melanoma growth than Lsp1 Tg T cells when adoptively transferred into Rag1 KO mice, which suggests that Lsp1-manipulated T cells have therapeutic potential. Here, RAG1 is linked to neoplasm.