E76K SHP-2 expression increases HPP-CFC and LPP-CFC growth. C-kit⁺ bone marrow cells expressing WT or E76K SHP-2 were cultured with saturating concentrations of SCF, M-CSF, IL-1, and either GM-CSF (A) or IL-3 (B). The number of HPP-CFC and LPP-CFC colonies are plotted per 2000 cells. ^*Significant differences between cells transduced with E76K versus WT SHP-2 retroviral constructs (P < .05). Error bars indicate the standard deviations of duplicate plates.