IDH1 and IDH2 gene mutations have been detected in gliomas, acute myeloid leukemia etc, resulting in inactivation of IDH leading to tumorigenesis.18, 19 IDH3 has been demonstrated to play an important role in tumor metabolism reprogramming in recent studies,3, 4, 6 and also considered as lung cancer gene.20 [18F]‐FDG PET/CT is a less invasive imaging tool widely used in the diagnosis and staging of malignant tumors. The gene discussed is IDH2; the disease is lung cancer.