Scientists at Israel’s Weizmann Institute have discovered that senescent (damaged) cells promote inflammation, common in age-related diseases. Absence of the LMNA gene (that kills senescent cells) causes premature aging. Treatment to destroy these cells (e.g. boosting immunity), slows aging.
https://wis-wander.weizmann.ac.il/life-sciences/immune-system%E2%80%99s-fountain-youth