FOXO4-DRI is a synthetic 46-residue D-retro-inverso peptide and one of the most studied compounds in senolytic research. Interest centres on cellular senescence, where the peptide is investigated as a decoy that competes with FOXO4 for the p53 binding surface, and on the question of why senescent cells containing an active death signal do not act on it. Its all-D, reversed-sequence construction gives resistance to proteolysis, while a TAT-derived segment assists cell entry, making it a practical subject for ageing and apoptosis research. For research use only.