Unlike acute prostatitis, where all cases show an increase in PSA levels [17], there are reports of two of seven cases of PA without an increase in PSA levels [18]. Cases of PAs caused by S. aureus without fever have been reported in the literature [9], but the underlying mechanism has not been elucidated. In this case, pus drainage from the ejaculatory duct orifice, albeit a small amount, may have reduced tissue destruction, partially explaining the absence of fever and PSA elevation. The gene discussed is KLK3; the disease is prostatitis.