Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive orphan hematologic cancer with a poor prognosis, and is derived from plasmacytoid dendritic cells that overexpress interleukin-3 receptor subunit alpha (IL3RA or CD123). The gene discussed is IL3RA; the disease is hematopoietic and lymphoid cell neoplasm.