PDCD1 and acute myeloid leukemia: It has been reported that several receptors including BTLA, 2B4, LAG-3, CD160, TIM-3 and PD-1 are upregulated on the T-cell surface to mediate T-cell exhaustion in a variety of tumors.18 To determine whether these exhaustion markers associate with AML relapse post transplantation, we performed flow cytometric analysis of these molecules using PBMCs from 11 patients post alloSCT, among whom 5 had leukemia relapse whereas the other 6 remained in remission at the time of sample collection.