THP-1 cells were divided into two groups: untreated group that comprised control cells treated with PMA (2.5 ng/mL) for 48 h] and FC-99-treated group that comprised FC-99 (10 μM) treatment 2 h prior to 48 h PMA (2.5 ng/mL) treatment. (A) All cells were harvested for flow cytometry analysis in order to detect the differentiation of markers, indicating the effect of FC-99 on the expression of macrophages, surface markers, CD11b and CD14, in THP-1 monocytes. (B) qRT-PCR displayed the expression of the differentiation-associated genes, CD11b and CD14. (C) Giemsa staining images were acquired using an optical microscope (original magnification, 200×), indicating the degree of monocyte differentiation into macrophages. The results were represented as means ± SEM from four independent experiments. *P < 0.05; **P < 0.01; ***P < 0.001, vs. control group.