TIGIT and melanoma: Inhibition of TIGIT with neutralising antibodies in lung colonisation experiments of 4T1 mammary cell lines or B16 melanoma cells or carrying out the experiments in TIGIT knockout mice reduces lung tumours and extends survival.49 One study found that anti-TIM-3 was required in Tigit–/– mice to reduce experimental lung metastasis of B16 cells.50 CD8+ T cells also express TIGIT,51 making it an ideal immunotherapy target to boost the anti-tumour functions of two cytotoxic cell types.