Two representative examples of BPDCN patients. Live cells are gated on a first forward scatter (FCS)/side scatter (SSC) to exclude debris and a FCS area (A)/FSC height (H) gate to select singlets (not shown). The CD45^bright /SSC^low cells are lymphocytes (blue), and CD45^dim /CD123^bright cells are a BPDCN blastic population (pink). (A) Patient P165. Blasts are CD4⁺ (lower than T lymphocytes in blue) and CD56⁺ with a bimodal expression, CD303⁺, CD304⁺ HLA-DR⁺, cTCL1⁺, ILT7^low, CD36⁺, CD38⁺, and CD43⁺.There is no expression of classical dendritic cell markers (CD1c, CD141, and CD11c) or immature markers (CD34, CD133, and Tdt). (B) Patient P149. Blasts are CD4⁺ and CD56^{partial and low}, CD303⁺, CD304⁺ HLA-DR⁺, cTCL1⁺, ILT7⁻, CD36^−/partial, and CD38⁺. The blasts also expressed CD7 and CD33 without CD13. Classical dendritic cell markers (CD1c, CD141, and CD11c) and immature markers (CD34 and CD133) are negative. APC, allophycocyanin; FITC, fluorescein isothiocyanate; PE, phycoerythrin.