The effect of PTEN overexpression on proliferation of LPS-induced lung fibroblasts. The effect of overexpression of PTEN on lung fibroblast proliferation at 72 h after 1 μg/mL LPS challenge was detected using MTT and Flow cytometry assays (3A, MTT assay. 3B and 3C, Flow cytometry assay). bpV(phen)(1 μM for 0.5 h) was examined to investigate the effect of overexpression of PTEN on lung fibroblast proliferation. PI3-K inhibitor Ly294002 (50 μmol/L for 1 h) was used to assess the effect of PTEN overexpression and PI3-K-Akt pathway inhibition on lung fibroblast proliferation in the presence or absence of LPS. *p < 0.05 vs. Blank and Empty group; †p < 0.05 vs. PTEN group; ‡p < 0.05 vs. PTENLPS group. §p < 0.05 vs. PTEN group; ||p < 0.05 vs. PTENLPS group. Columns represented mean values and error bars represented SD. Flow cytometry graphs shown in Figure B were representative of three independent experiments.