Cell growth proliferation was assessed by BrdU incorporation analysis. BrdU-positive cells, stained green. The number of positive cells reflects the ability of proliferation. However, no change of the number of BrdU -positive cells was observed in the Notch1 down- expression group or Notch1 high expression group compared to the control group. The results demonstrated that Notch1 down-regulating expression or high expression did not have any effect on cell proliferation.