The evaluation of TIGIT expression on both Foxp3⁻CD4⁺ and Foxp3⁺CD4⁺ T cell populations was undertaken. In a cohort of mice (n = 6), each receiving an i.p. injection of 1 × 10⁶ ID8 cells, peritoneal lavage fluid and spleen samples were collected seven days post-injection from both ovarian cancer and normal mice (n = 6). Mononuclear cells were isolated via Ficoll-Paque density gradient centrifugation. Flow cytometry was utilized to assess the proportions of TIGIT⁺Foxp3⁺CD4⁺ and TIGIT⁺Foxp3⁻CD4⁺ lymphocytes within the spleen and ascites (A). Additionally, the frequency of TIGIT⁺ cells within Foxp3⁺ and Foxp3⁻ CD4⁺ T cell subpopulations found in the spleen and ascites was examined (B). The results are depicted as means ± standard deviation. OC, ovarian cancer