CXCR6 and neoplasm: For instance, CXCR3 and CCR5 have been shown to be involved in T-cell trafficking into the tumors (11–13), whereas CXCR6 is involved in providing survival signals to T cells in the tumor microenvironment (14, 15), and CXCR5 in the migration of T cells into tertiary lymphoid structures (TLS; refs. 16, 17).