FOXO4-DRI (FOXO4 D-retro-inverso peptide, also listed as Proxofim) is a cell-permeable peptide designed in 2017 to perturb the interaction between the transcription factor FOXO4 and p53. It is built from D-amino acids in retro-inverso order and combines a FOXO4-derived region with a cationic cell-penetrating sequence. It is studied as a senolytic research tool, meaning a compound that selectively removes senescent cells. Published work covers mouse models of chemotoxicity and ageing, senescent cell cultures, structural biology, and mouse models of pulmonary fibrosis and pulmonary hypertension.