For example, global knockout of Pex3 and germ cell-specific knockout of Pex13 arrested sperm production at the spermatid stage with the formation of multinucleated giant cells (MGCs) and loss of mature spermatids[12–13]; Sertoli cell-specific silencing of Pex5 decreased the number of spermatozoa in the lumen of seminiferous tubules and increased the formation of large lipid droplets in Sertoli cells[14]; mice with a mutation in peroxisomal biogenesis factor 7 (Pex7) exhibited testicular atrophy primarily characterized by the devoid of spermatogonia and spermatocytes[15]. This evidence concerns the gene PEX7 and Testicular atrophy.