TIMP3 and age-related macular degeneration: Additionally, Tissue Inhibitor of Metalloproteinases 3 (Timp3) which was also found to be downregulated in exercised mice, has been heavily implicated as a potential candidate in AMD pathogenesis, with elevated levels seen to contribute to the thickening of Bruch’s membrane commonly seen in AMD patients (Kamei and Hollyfield, 1999).