Although synergistic antitumor efficacy of anti-CTLA-4 Ab and anti-PD-1 Ab has been observed in a CT26 tumor model64, we did not see the difference of tumor control or the frequency of PB CX3CR1+ CD8+ T cells in mice treated by monotherapy or combined therapy (Fig. 1e, f). Here, CTLA4 is linked to neoplasm.