Anti-TNF–treated GTS cultures contain myeloid progenitors with CFU potential on day 10. Cells removed from anti-TNF–treated GTS cultures on day 10 and placed in methylcellulose with GM-CSF+SCF yielded colonies resembling mono CFU (a) and granulocyte CFU (b). Nonspecific esterase (c) and Wright stain (d) analysis confirmed the presence of both mono-macrophages and granulocytes. Original magnification for (a), (b), and (d) = 40×, for (c) = 60×. Cells removed from untreated GTS cultures on day 10 and cultured in parallel failed to yield CFU.