FG-4497 decreases HSPC proliferation in vivo. A total of 20 mg/kg of FG-4497 (black bars) or saline (white bars) was administered daily into C57BL/6 mice for 6 days. BrdU was administered in the drinking water for the last 3 days of the experiment. (A) Percentage of BrdU⁺ cells. Data are show as the means ± SD from 5 mice per group. (C) Typical BrdU incorporation profiles for saline-treated (gray) and FG-4497–treated (black) mice. (B,D) Cell-cycle analysis on LKS⁺48⁺ HPCs and LKS⁺48⁻ HSCs from mice treated with FG-4497 or saline. Representative dot plots showing the proportion of cells in each phase of the cell cycle after in vivo treatment with FG-4497 or saline. Data are shown as the means ± SD from 5 different mice per treatment group. Significance levels were calculated using a t test.