1.

Effect of IGF-1 stimulation on the determination of R-point based on cyclin E expression. Cyclin E expression marks the R-point, which occurs at G1/S transition. Thus, cyclin E accumulation is used to assess the R-point. SV (left panel) and IMA (right panel) SMCs were stimulated with IGF-1 (100 ng/ml) over a time course of 0–5 hrs. Cyclin E levels were determined by Western blotting and the results are graphically represented as densitometric analysis of five individual samples of SV and IMA cells. (**P < 0.001)