Acid phosphastase is an enzyme found in semen, bone, liver, spleen, kidney, RBCs and Platelets. Highest amount is found in semen. Increased in Prostate cancer, Gaucher & Nieman-Pick disease, Benign prostatic hyperplasia (BPH), Infarct of prostate. It is also elevated after manipulations of the prostate like catherisation, biopsy and surgery.