The TF-1 cell line has been established by T. Kitamura in October 1987 from a heparinized bone marrow aspiration sample from a 35 year old Japanese male with severe pancytopenia. They dont respond to interleukin 5 (IL-5), but to a variety of other lymphokines and cytokines such as interleukin 1 (IL-1), interleukin 4 (IL-4), interleukin 6 (IL-6), interleukin 9 (IL-9), Interleukin 11 (IL-11), interleukin 13 (IL-13), stem cell factor (SCF), leukemia inhibitory factor (LIF) and nerve growth factor (NGF). The morphological and cytochemical features, and the constitutive expression of globin genes, indicate the commitment of the cells to the erythroid lineage. TPA induces a dramatic differentiation into macrophage-like cells; Hemin and delta-aminolevulinic acid induce hemoglobin synthesis.