PDCD1 and acute myeloid leukemia: To examine whether there is an association between the expression of Blimp-1 and multiple inhibitory receptors in AML, PBMCs collected from AML patients were co-cultured with Blimp-1 probe followed by co-staining with antibodies to inhibitory receptors including PD-1, TIGIT, 2B4, CD160, and TIM-3.