Figure 3. Results of real time PCR. Expression of Bmi1, Ki67, and p16^INK4a in HCECs from donors of different ages analyzed by real-time PCR (A). There was a statistically significant difference in p16^INK4a expression between the donors of younger than 30 years and older than 50 years of age (p≤0.001). There was also a statistically significant difference in Ki67 expression between donors of younger than 30 years and donors older than 50 years of age (p≤0.001). The figure depicts a Pearson correlation of p16^INK4a gene expression with age (r=0.560, p=0.001; B).