MTAP is an enzyme essential for the salvage pathway for both adenine and methionine synthesis. MTAP catalyzes the cleavage of 5’-methylthioadenosine into adenine and 5-methylthio-D-ribose-1-phosphate. Adenine is then used to generate AMP whereas 5-methylthio-D-ribose-1-phosphate is converted into methionine. MTAP is expressed in all normal cells and tissues, although frequently lost in different human tumors including pancreatic adenocarcinoma, neuroendocrine tumors, non-small cell lung carcinoma and breast carcinoma, thereby implicating its potential function as a tumor suppressor.