IDH-mutant tumors have aberrant production and accumulation of the oncometabolite 2-hydroxyglutarate (2-HG), which may play a pivotal oncogenic role in several malignancies including AML, central nervous system and billary tract. Strikingly, IDH1 mutations were rarely detected in the other solid tumor types. Reports have shown that melanoma cases can harbor IDH1 mutations. An IDH1 R132C mutation was found in a melanoma metastasis to the lung. IDH1 mutations were found to coexist with BRAF or KIT mutations, and all were detected in metastatic lesions. Coexistence of IDH1 R132C mutation with KRAS has also been reported in a single case of lung adenocarcinoma (Sequist et al., Ann Oncol., 22:2616–2624, 2011). The clinical significance of this mutation with regards to response to anti-IDH1 therapy in lung cancer is unknown.