c-kit⁺ lin^−/low cells have genotype-specific signaling profiles that vary with the cytokine stimulus. Serum- and cytokine-starved whole bone marrow from WT and Mx1-Cre, Kras^G12D mice was stimulated with GM-CSF (10 ng/mL) or SCF (100 ng/mL) for 10 or 30 minutes. Levels of phosphorylated ERK, STAT5, and S6 were measured using phospho-specific flow cytometry in the (A) whole marrow and (B-C) in the c-kit⁺ lin^−/low subset. The figure shows representative data from 10 independent experiments.