Although we used PSA as a marker of prostate infection/inflammation/cell damage, PSA may also possibly rise as a result of a more generalised response to infection at other non-prostate sites (e.g., urethra), recent ejaculation (within 1 day), or digital rectal examination (DRE; Tchetgen and Oesterling, 1997). The gene discussed is KLK3; the disease is infection.