It has been reported that significant decreases in PSA levels can be seen following empirical use of antibiotics both in patients with chronic prostatitis and asymptomatic prostatitis (Schaeffer et al., 2005; Erol et al., 2006; Kaygısız et al., 2006; Serretta et al., 2008; Baltacı et al., 2009; Kyung et al., 2010; Stopiglia et al., 2010). Here, KLK3 is linked to prostatitis.