FOLH1 and neoplasm: In complementary studies, other investigative groups have shown that RT-PCR for PSMA and prostate specific antigen (PSA) in peripheral blood was correlated with tumor stage and that elevated amplicon levels were highly predictive of primary tumor extension beyond the capsule of the prostate [30], and similarly PSMA RT-PCR on peripheral blood has been shown to correlated with a higher tumor grade at diagnosis [31].