Fig. 1

Effects of different concentrations and durations of epidermal growth factor (EGF) on the proliferation of HaCaT and L929 cells. a. Observation of HaCaT cells at day 2 under an inverted microscope. b. The effects of different concentrations (0, 1, 5, 10, and 100 ng/ml) of EGF on the proliferation of HaCaT cells at different time. c. The effects of different duration (2, 10, and 30 min) and a set concentration (10 ng/ml) of EGF on the proliferation of HaCaT cells at different time. d. Observation of L929 cells at day 2 under an inverted microscope. e. The effects of different concentrations (0, 1, 5, 10, and 100 ng/ml) of EGF on the proliferation of L929 cells at different time. f. The effects of different duration (2, 10, and 30 min) and a set concentration (10 ng/ml) of EGF on the proliferation of L929 cells at different time. Data are shown as means ± SD, *P < 0.05, **P < 0.01