Effect of ZOL on the differentiation of JMML and normal BM cells in the suspension culture. (A) Effect of ZOL on the proportion of α-NBE–positive and –negative cells in the suspension culture of JMML and normal BM cells. Each value indicates the mean calculated from the data for 3 patients with JMML and 3 healthy donors. NS indicates not significant. ▪ indicates α-NBE-positive cells; ▦, α-NBE-negative cells. (B) Appearance of α-NBE–positive and –negative cells in the suspension culture of BM cells of a patient with JMML (case 4) and a healthy donor (case 5) without and with 10 ng/mL GM-CSF (microscope, BH2, Olympus; camera module, DP70, Olympus; objective lens, Span, Olympus; numerical aperture, 0.7; magnification, × 40). α-NBE–positive macrophages possess brown granules in their cytoplasm.