Table 2. Summary of the fold differences in p16-positive and p21-positive cells in middle-aged and old participants relative to young.
| Anatomic site | p16 | p21 | ||||
| Young | Middle-aged | Old | Young | Middle-aged | Old | |
| Pancreas, exocrine | 1 | 1.52 | 2.41 | 1 | 1.45 | 7.12 |
| Pancreas, endocrine | 1 | 2.03 | 1.96 | 1 | 1.73 | 0.96 |
| Skin, epidermis | 1 | 0.73 | 21.41 | 1 | 3.41 | 4.80 |
| Skin, dermis | - | - | - | 1 | 2.47 | 7.73 |
| Kidney | 1 | 2.67 | 7.21 | 1 | 3.89 | 10.97 |
| Liver | 1 | 0.37 | 2.16 | 1 | 0.19 | 0.99 |
| Intestine (colon) | 1 | 1.67 | 1.73 | 1 | 1.40 | 1.68 |
| Spleen | 1 | 0.50 | 4.17 | - | - | - |
| Brain Cortex | 1 | 2.81 | 3.27 | - | - | - |
| Lung | 1 | 1.43 | 1.37 | 1 | 0.85 | 0.98 |
(-): no positive cells found.