EP induces differentiation of leukemia cell lines. (A) Representative morphology of HL60 cells treated for 72 hours without EP, with EP, or with TPO shown at 20× (left panel) and 63× (right panel). Cells treated with EP portray reorganization of the nuclear contents compared with untreated cells (red arrows) and cells treated with TPO. (B) The fold change of FACS MFI ± SD (n = 3) of CD11B expression (i) and CD14 (ii) in HL60 cells treated with the above conditions relative to untreated cells for 72 hours. *P < .05; **P < .01; ***P < .001. FACS analysis of CD11B expression (iii) in untreated HL60 cells (blue line) versus cells treated with 5 μg/mL of EP (orange line) for 72 hours. FACS analysis of CD14 expression (iv) in untreated HL60 cells (green line) versus cells treated with 5 μg/mL of EP (orange line) for 72 hours. CD11B and CD14 are overexpressed with EP treatment. (C) Representative morphology of U937 cells and URE cells treated for 72 hours under the above conditions. U937 cells treated with EP demonstrate increased size with increased vacuoles in the cytoplasm. (D) The fold change of FACS MFI ± SD (n = 3) of CD11B expression in U937 cells and URE cells treated with or without EP for 72 hours. *P < .05; **P < .01.