In the pre-clinical mice TIGIT negative mice bearing colon cancer (MC38 model), co-blockade of TIGIT and PD-1 was associated with enhanced effector cell functions of both CD4+ and CD8+ T cells compared to either therapy alone; and TIGIT/PD-1 co-blockade produced a 100% cure rate [123]. This evidence concerns the gene PDCD1 and malignant colon neoplasm.