Figure 6. Effect of siRNA treatment on cell cycle entry and cell division. HCEC were treated with control or p21+p16 siRNA. On Days 1, 5, and 11, cells in the same 20× microscopic field were counted to determine the average percent of Ki67-positive cells, as an indication of the effect of treatment on cell cycle entry (A) and the average total number of DAPI-stained nuclei, as an indication of cell division (B). Data represents the average results from five different donors. Brackets on each bar represent SEM. P-values are indicated for each condition and time point.