TIGIT and neoplasm: In tumour Treg cells, both anti-TIGIT isotypes drove downregulation of immunosuppressive and Treg-cell-associated genes such as Il10, Ctla4 and Tnfrsf1b relative to treatment with anti-PD-L1 antibodies or control, and sustained those effects in combination with anti-PD-L1 (Fig. 4d).