Capture of erythroid progenitor cells expressing GPA by CD11c⁺ cells from bone marrow of hemophagocytic syndrome. Bone marrow smear preparations from patients with hemophagocytic syndromes were stained with CD11c (red)/GPA (brown) for patient 1 (A) or CD11c (brown)/GPA (red) for patient 2 (B) and patient 3 (C). The arrows indicate GPA-positive erythroid cells. Staining with α-NB of hemophagocytic cells is also shown in patient 3 (D) and DCs generated from purified normal human CD34⁺ cells in the presence of TPO and TNF-α (day 5 [E]; day 7 [F]).