Effects of ATO and nilotinib on hemoglobin content. Cells were treated with 1 μM ATO and 5 nM nilotinib alone or in combination for 72 h. Then, cell samples were stained with benzidine. (A) The percentage of benzidine-positive cells was calculated. **P < 0.01 vs. control. (B) Representative data of benzidine staining (x200 magnification).