Reissigl et al. [20] reported that using the age-specific PSA cut-off proposed by Oesterling et al. resulted in an 8% increase in the number of biopsies and an 8% increase in organ-confined cancer detection in men aged 45–59 years, while in older men aged 60–75 years, it resulted in about a 21% reduction in biopsies but would result in 4% of prostate cancers being missed. The gene discussed is KLK3; the disease is prostate cancer.