Figure 2. Effect of treatment with 3 different p21 siRNAs on p21Cip1 and p16INK4a protein levels. The graph of western blot results in (A) shows the effect of p21 siRNAs s415, s416, and s417 on the protein level of p21Cip1. The graph in (B) shows the effect of the same 3 p21 siRNAs on the protein level of p16INK4a. In the graphs, each bar shows the average relative expression of p21Cip1 or p16INK4a (+/− SEM) in HCEC cultured from 3 older donors. Beta-actin was used to normalize all results. Conditions included no electroporation or siRNA treatment (-E/-siRNA), electroporation with Silencer Cy3-labeled Negative Control #1 siRNA (+E/Cy3control), and electroporation with each of three siRNAs (+E/p21 s415, s416, or s417).