CD123 has been found to be extensively overexpressed not only in AML but also in other hematological malignancies, such as blastic plasmacytoid dendritic cell neoplasm (BPDCN), MDS, systemic mastocytosis, chronic myeloid leukemia (CML), acute lymphoblastic leukemia (ALL), and hairy cell leukemia (HCL) [101,102,103,104,105,106,107]. The gene discussed is IL3RA; the disease is hairy cell leukemia.