For these reasons, a high proportion of men with a raised PSA go on to receive a negative biopsy result – for example, 75% of men with a PSA test of ⩾3 ng ml−1 who had a biopsy in the European Randomised Study of Screening for Prostate Cancer (Schröder et al, 2009). Here, KLK3 is linked to prostate carcinoma.