Stem cell factor (SCF), also known as mast cell growth factor (MGF), and steel factor (SLF), plays an important role in hematopoiesis, spermatogenesis and melanogenesis. SCF has been shown to??stimulate?the proliferation of TF-1 cells. To test this effect,?TF-1 cells were seeded into triplicate wells of 96-well plates and incubated for 72h in the presence or absence of various concentrations of SCF at 37℃The growth of cells were observed by inverted microscope and cell proliferation was measured by Cell Counting Kit-8(CCK-8). Briefly, 10 μl of CCK-8 solution was added to each well of the plate, then measure the absorbance at 450 nm using a microplate reader after incubating the plate for 1-4 hours at 37℃. Cell proliferation of TF-1 cells after incubation with SCF for 72h observed by inverted microscope was shown in Figure 1. The dose-effect curve of SCF was shown in Figure 2. It was obvious that it significantly promoted cell proliferation of TF-1 cells. The EC50 for this effect is typically 8.1 ng/ml.