Highlights A modified FOXO4-p53 interfering peptide causes p53 nuclear exclusion in senescent cells This FOXO4 peptide induces targeted apoptosis of senescent cells (TASC) TASC neutralizes murine liver chemotoxicity from doxorubicin treatment TASC restores fitness, hair density, and renal function in fast and naturally aged mice Summary The accumulation of irreparable cellular damage restricts healthspan after...