RICTOR is part of the RICTOR-mTOR protein complex which is involved in the phosphorylation and regulation of the AKT/Protein Kinase B (PKB) which in turn triggers cell proliferation and cell survival. Amplification of the RICTOR gene region leads to a dysregulation of PKB, known to be a responsible factor in tumor pathogenesis. In 8-13% of non-small cell lung carcinomas (NSCLC) and small cell lung cancer (SCLC) an amplification of the RICTOR gene region has been demonstrated. Amplifications of the RICTOR gene region represent one of the most abundant genetic events in SCLC patients. Hence, RICTOR amplifications have been proposed as biomarker for a targeted therapy with mTOR inhibitory agents in patients diagnosed with lung cancer. Fluorescence in situ Hybridization may be a suitable diagnostic tool for the detection of RICTOR amplifications.