Cellular interventions independently extend lifespan

This proposed longevity hypothesis asks whether three strategies retain distinct benefits: mitochondrial recycling, maintaining energy-producing structures in tissue cells; secretion restraint in senescent fibroblasts, support cells that stopped dividing; and immune removal of senescent cells that impair repair. Key prediction: secretion restraint still improves function and survival when mitochondrial recycling and senescent-cell number are held constant. Immune removal requires antigen presentation, a display that lets immune cells identify targets. Blocking it should stop removal and lasting benefit; restoring it should restore both. Testing needs controlled mediator changes, assays of antigen display and immune-cell killing, functional tests, and survival studies.