Mayo Clinic researchers have discovered that senescent cells — non-dividing zombie cells — build up in the skin as we age and can influence the aging process in other parts of the body. Their latest study showed that transplanting aging skin cells in a preclinical model not only led to the spread of aging to other tissues, but also accelerated physical decline, impaired muscle function, and worsened brain health. This discovery suggests that senescent cells in the skin could cause wider systemic aging.