Sin3B is required for the maintenance of HSC quiescence. (A) Representative FACS plot of intracellular Ki67 staining and DNA content (DAPI) in control and Sin3B^CKO HSCs. (B) Quantification of the distribution of HSCs in the G0, G1, and S/G2/M phases of the cell cycle; n = 4. (C) Representative FACS plot of BrdU incorporation in control and Sin3B^CKO HSCs. (D) Quantification of BrdU incorporation of indicated cell populations; n = 3. Data are represented as mean ± SEM. *P < .05; **P< .01.