Knockout of Icmt reduces growth factor-independent colony growth of bone marrow cells from mice with K-RAS–induced MPD. (A,B,D) Methylcellulose colony assays of bone marrow cells (n = 3-5 for each genotype) cultured in the absence (A) and presence (B) of growth factors (SCF, IL-3, IL-6, and EPO), and the indicated concentrations of GM-CSF (D). (C,E) Colony growth of bone marrow cells from Icmt^fl/+M (n = 3) and Icmt^fl/flM mice (n = 3) (without the Kras2^LSL allele) cultured in the presence of growth factors (C) or the indicated concentrations of GM-CSF (E). (F) BFU-E formed by bone marrow cells (n = 2 for each genotype) cultured in the indicated concentrations of EPO. (G,H) PCR amplification of genomic DNA from individual colonies. The genomic DNA used in panel G is from colonies from experiments in Figures 3D and 5B. DNA used in panel H is from experiments in panel C.