ALT, which is present mainly in the cytosol of liver and much less in the other tissues, is the most specific for liver disease [6], whereas AST, which has cytosolic and mitochondrial forms, is less specific for liver disease as it is found, in addition to the liver, in the heart, skeletal muscle, kidneys, brain, pancreas, lungs, leukocytes, and erythrocytes. The gene discussed is GOT1; the disease is liver disorder.