p185-expressing primary mouse bone marrow cells expanded with cytokines and stroma differentiate into pre-B cells after cytokine withdrawal, whereas p210-and p230-expressing cells differentiate into myeloid/monocyte cells under the same conditions.

Two days after retroviral-mediated gene transfer, primary mouse bone marrow cells were expanded in the presence of autologous stroma and cytokines. After 12 days, nonadherent cells were replated in the absence of cytokines. Thirty-two days after replating (44 days after retroviral-mediated gene transfer), GFP-positive cells were subjected to cytospin and Wright's stain (A) or flow cytometry (B) to detect expression of the indicated cell surface markers.