Imatinib is specific tyrosine kinase receptor inhibitor that is used in the therapy of Philadelphia chromosome-positive chronic myelogenous leukemia and gastrointestinal stromal tumors, both of which are marked by an abnormal, constitutively expressed tyrosine kinase that causes unregulated cell growth. Imatinib therapy is associated with transient elevations in serum aminotransferase levels and rare instances of clinically apparent acute liver injury which can be severe and sometimes fatal.