However, elevated serum PSA levels are also found in patients with benign prostatic hyperplasia (BPH) and prostatitis (Zackrisson et al., 2003; Kawakami et al., 2004; Agnihotri et al., 2014), as well as in healthy males after ejaculation, prostate biopsy and exercise (Mejak et al., 2013). The gene discussed is KLK3; the disease is benign prostatic hyperplasia.