PDCD1 and acute myeloid leukemia: Ipilimumab is currently evaluated in several clinical phase I trials as a treatment for relapsed/refractory AML patients (NCT03912064, NCT03600155, NCT01822509) and as maintenance therapy for AML and MDS patients alone or in combination the anti-PD-1 antibody Nivolumab and/or azacitidine after allogeneic HSCT (NCT02846376) and for its potential to induce graft-versus-malignancy effects after allogeneic HSCT (NCT00060372).