Effects of ASXL1 mutations on the differentiation of PMA-treated U937 cells. Following treatment with various concentrations of PMA, cells were harvested at 96 h. (A) Representative images of Wright-Giemsa-stained WT and ASXL1-mutated U937 cell lines, which attached to chamber slides following 200 ng/ml PMA-induced differentiation. (B) CD11b expression in cells harvested from slide chambers, as determined by flow cytometric analysis. (C) Percentages of CD11b-positive cells in WT and MT U937 cells calculated using flow cytometry data. Data are presented as the means ± standard error of the mean. *P<0.05 vs. the WT group (WTblk, WT1 and WT2), one-way analysis of variance. ASXL1, additional sex combs-like 1; CD11b, cluster of differentiation 11b; PE, phycoerythrin; PMA, phorbol 12-myristate 13-acetate; MT, mutated; WT, wild-type; WTblk, wild-type bulk parental.