Our body is constantly repaired and renewed by tissue specific stem cells, which produce cells undertaking specialized functions, and new stem cells maintaining the future renewal capacity. In a young body, such tissue stem cells can easily counter the wear and tear of everyday life by replacing damaged cells with new ones. However, as we age, capacity of stem cells declines, and the resulting drop in tissue repair manifests as the functional decline associated with aging. Our goal is to understand why stem cell activity deteriorates with age, and to develop stem cell based strategies targeting aging related diseases and ailments.