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 Analysis of the 2 predicted binding pockets of FOXO4 DRI. (A) Surface Download Scientific Diagram FOXO4 DRI improves spermatogenesis in aged mice through reducing senescence associated secretory phenotype secretion from Leydig cells ScienceDirect 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.