Alkaline phosphatase - There are four major sources of Alkaline phosphatase in the body. These are:-Liver        Bone     Intestine PlacentaSo the normal serum alkaline phosphatase consists of 4 isoenzymes secreted from the above-mentioned sites. Placental alkaline phosphatase is elevated in the following conditions - (a) Seminoma   (b) Choriocarcinoma (c) Third trimester of pregnancy About other options - In liver diseases and hepatocellular carcinoma the alkaline phosphatase elevated is of liver origin. Similarly the alkaline phosphatase elevated in bony diseases is due to some pathology in bone.