Growth inhibition of NIH3T3 cells. (A) NIH3T3 cells (2 × 10³/well) were cultured in the presence of various concentrations of mOSM (○), hOSM (▵), mLIF (•), and hLIF (▴) for 4 days in 96-well multiwell plates. Cell growth was monitored by the MTT assay. (B) Time course of cell growth in the presence of mOSM. NIH3T3 cells (4 × 10⁴/well) were incubated in the absence (□) or presence of mOSM (○) or hOSM (▵) in 24-well multiwell plates. Viable cell numbers were counted daily by the trypan-blue exclusion method. Data are averages of duplicate measurements.