IGFBP2-null mice have fewer HSCs than wild-type mice. The frequencies of BM Lin⁻Sca-1⁺Kit⁺ cells, ST-HSCs/MPPs as Lin⁻Sca-1⁺Kit⁺Flk2⁺CD34⁺ cells, and LT-HSCs as Lin⁻Sca-1⁺Kit⁺Flk2⁻CD34⁻ cells in IGFBP2-null and WT male littermates (A; n = 8) and female littermates (B; n = 7-8) were compared. (C) The frequencies of BM progenitors CMP, GMP, MEP, and CLP in IGFBP2-null and WT mice (n = 4-5) were measured.