The results we report here on the discriminating capabilities of urine VOCs are somewhat inconclusive, but they mirror the findings of other groups that have tested potential biomarkers in urine and blood (PCA3 [55], multiplex urine RNA based biomarkers [56], and the Prostate Health Index based on PSA and its derivative [–2]proPSA and %fPSA [57, 58]) for the discrimination of prostate cancer patients from controls. This evidence concerns the gene KLK3 and prostate cancer.