Id1 expression in myeloid lineage cells. Indicated bone marrow subsets were gated as shown in Figure S1. The definitions of the subsets are as follows: LSK, Lin⁻Sca-1⁺c-kit⁺; LMPP, Flt3^HiLSK; CMP, Lin⁻Sca-1⁻c-kit⁺CD34⁺FcγR⁻; MEP, Lin⁻Sca-1⁻c-kit⁺CD34⁻FcγR⁺; GMP, Lin⁻Sca-1⁻c-kit⁺CD34⁺FcγR⁺; CLP, Lin⁻Sca-1⁺c-kit^loIL7R⁺. Histograms of GFP fluorescence in Id1^G/G cells (solid line) were superimposed on those in wild-type cells (dotted line). Data are representative of at least 3 independent experiments.