CD226 and neoplasm: In the TC1 tumors treated with αTIGIT and bintrafusp alfa, we observed a significant reduction in TIGIT expression on CD4+ T cells (p = .0123) and a trending decrease in TIGIT expression in Treg cells, which were associated with the significant reduction in the bioavailable TIGIT-to-CD226 ratio on these tumor infiltrating cells (p = .0029 and p = .0459, respectively; online supplemental figure 3B-3C).