Human PAP, His tag

Prostatic acid phosphatase (PAP), also prostatic specific acid phosphatase (PSAP), is an enzyme produced by the prostate. It may be found in increased amounts in men who have prostate cancer or other diseases. PSAP was used to monitor and assess progression of prostate cancer until the introduction of prostate specific antigen (PSA), which has now largely displaced it. Subsequent work, suggested that it has a role in prognosticating intermediate and high-risk prostate cancer, and led to renewed interest in it as a biomarker.