PDCD1 and colorectal carcinoma: Moving forward, we propose that future studies should validate the prognostic significance of TIGIT+PD-1+CXCL13+ CD8+ T cells across independent CRC cohorts, evaluate their detectability in peripheral or cytological specimens, and investigate their dynamic changes in response to TIGIT blockade—alone or in combination with PD-1/PD-L1 inhibitors.