Expression of CD4 and CD14 on macrophage-like cells derived from transduced CD34⁺ cells. CD34⁺ cells transduced with either the LNL6 (A) or ribozyme 9456 (B) retroviral vectors were cultured in methylcellulose in the presence of G418 and then replated in liquid culture supplemented with GM-CSF, M-CSF, and G418. Macrophage-like cells derived from these cultures were then analyzed for expression of CD4 and CD14 by flow cytometry.