In another study performed on patients with varicocele who smoked, Fariello and colleagues identified five proteins related to apoptosis regulation in moderate smokers (annexin A3 (ANXA3), cathepsin B (CTSB), epididymal secretory protein E3-ß (EDDM3B), prostaglandin-H2 D-isomerase (PTGDS), and extracellular superoxide dismutase (SODE)). Here, PTGDS is linked to varicocele.