TIGIT and neoplasm: Even so, it is unlikely that the combined PD-1/TIGIT blockade can sufficiently elicit robust antitumor responses as preclinical mouse models show that reductions in tumor growth were only achieved after addition of aCD40 to the coblockade of TIGIT/PD-1.203 Another study using a neoantigen vaccine approach in a KRAS-driven mouse model linked slowing of tumor growth to increases in neoantigen-specific T cells expressing high levels of TIGIT and PD-1, whereas subsequent coblockade of TIGIT/PD-1 enhanced immune responses.204