Some fibroblasts are known to secrete the growth factor for epithelial cells. To elucidate the properties and the biological role of the growth factor, its proteins were purified. One human fibroblast, M426, produces two proteins (MW 68,000 and MW 18,000), each of which was purified to a homogeneous state by column chromatography and fast protein liquid chromatography (FPLC).
