Targeting of the decorin gene expands the numbers of rigorously defined HSCs and extramedullary hematopoiesis. (A-B) BM cells were prepared from 7- to 9-week-old decorin-deficient (KO) and control (WT) mice. Without initial separation, the samples were stained for lineage-associated (Lin) or other surface markers as indicated. The stem/progenitor cell enriched Lin⁻Sca-1⁺c-Kit^hi (LSK) category of cells was subdivided according to Flk-2, CD34, or CD150 expression. Incidences or total numbers of each subset are given in panel B. These represent pooled results using a total of 9 mice of each kind in 3 independent experiments. (C-D) CD150⁺ or CD150⁻Flk-2⁻ LSKs were cultured under stromal cell–free, serum-free conditions to analyze myeloerythroid potentials (C) or B-lymphoid potentials from CD150⁻Flk-2⁻ LSKs (D). Similar results were obtained in 3 independent experiments. (E) Weights and numbers of LSKs in spleens are given in the left and right panels. (F) Splenocytes were also cultured in cytokine-containing methylcellulose medium for 1 week. Statistical significance was determined by unpaired 2-tailed t test analysis. *P < .05; **P < .01.