Previous single-cell sequencing of CD45 + HLA-DR + CD123+ blasts from four BPDCN patients revealed that BPDCN is most closely related to pDCs, with expression of B-cell markers, such as FCRLA, IGLL1, TCL1A, and IGLL526. The gene discussed is FCRLA; the disease is CD4+/CD56+ hematodermic neoplasm.