Nonetheless, proteins, such as CLGN, FTH1, MDH1, MIF, PPP3CA, SUCLA2, and PSMA7, involved in sperm function, apoptosis, and oxidative stress were present in a low and very low abundance in the unilateral and bilateral varicocele group, respectively (Supplementary Table S2). This evidence concerns the gene FTH1 and varicocele.