Dose-response effects of 1,25S-(OH)₂-16,23E-diene-26-F₃-19-nor D₃ (Ro 25-9716) and 1,25-(OH)₂D₃(1,25D₃) on clonal proliferation of myeloid leukemia cell lines. Results are expressed as a percent of control plates containing no vitamin D₃ compounds. Results are the mean of at least three independent experiments with triplicate dishes. (□), 1,25 D₃; (⌾), Ro 25-9716.