PDCD1 and acute myeloid leukemia: This difference of co-expression in AML and MM was caused by the significant co-expression of PD-1 and TIM-3 on the TIGIT+ Vδ1 γδ T cells in comparison to their corresponding Vδ2 cells (AML: p = 0.01, p = 0.008 and MM: p = 0.01, p = 0.042; Figure 5B).