Figure 3. Immumofluorescence observation (100×) of PCNA (oval green spots) in rLEC treated with different doses of rapamycin. Panel A shows the control rLECs, while B, C, and D shows 0.1, 1, 10 ng/ml rapamycin, respectively, after a 24 h exposure. PCNA is clearly reduced in the rapamycin-treated group. The histogram (E) summarizes the results of scanning densitometry of PCNA. All differences were statistically significant, *p≤0.05.