FOXO4 DRI improves spermatogenesis in aged mice through reducing senescence associated secretory phenotype secretion from Leydig cells ScienceDirect Particle FOXO4 DRI (Proxofim) is a synthetic peptide with a retro inverted structure, developed as a modified version of the natural FOXO4 protein. Scientific interest in this compound is growing, especially within Buy FOXO4 DRI 10mg FOXO4 Research Peptide for Cellular Signaling Studies FOXO4 DRI Simple Peptide The FOXO4 peptide in a DRI conformation (D amino acids in a retro reversed sequence), henceforth named FOXO4 DRI, competes with FOXO4 for p53 binding in a dose dependent manner and doing so with higher affinity.