Figure 4. TIPE2 inhibits VSMC proliferation and prevents cell cycle entry/progression in the G₀/G₁ phase. (A) Proliferation ability is significantly increased in TIPE2^−/− VSMCs with or without ox-LDL treatment compared with WT controls. (B and C) TIPE2 prevents cell cycle entry/progression in G₀/G₁ phase in cultured VSMCs. (D) SMαA, PCNA and cell cycle proteins such as Cyclin D1, Cyclin E, P21 and P27 in VSMCs treated with PD/SB plus ox-LDL were determined by western blot. β-actin served as a loading control. Data shown are means ± SEM (n = 5) and are representative of three independent experiments. *p < 0.05, **p < 0.005, ***p < 0.001.