After observing the significant potential of metabolomics analyses to discriminate BCR status for the PGG2 group, we tested a number of other currently known clinical parameters, including pre-surgical PSA (mean 5.94 ng/mL), pT stage (II vs. III), and prostate cancer perineural invasion (+ vs. −), to assess their potential to provide further discrimination within the PGG2 group. The gene discussed is KLK3; the disease is prostate cancer.