IL3RA and hairy cell leukemia: Indeed, CD123 expression has been demonstrated on neoplastic cells in blastic plasmacytoid dendritic cell neoplasm (BPDCN), acute myeloid leukemia (AML), acute lymphoblastic leukemia/lymphoma (ALL), hairy cell leukemia (HCL), systemic mastocytosis (SM), etc. [1,5].