Studies on the effect of recombinant human interferon (rIFN) on the growth of colonies of multi potential hematopoietic progenitors have demonstrated that IFN inhibits the growth of these cells in culture. The inhibitory effect of IFN was more pronounced in multilineage colony forming cells (CFU-GEMMT) of marrow cells of patients with chronic myelogenous leukemia (CML) compared with stern cells of normal marrow. T cell colony formation (CFU-TL) of phi_positive T cells obtained from primary multilineage hematopoietic colonies was inhibited by rIFN. Inhibition of T cell colony formation of Phi...