In a past clinical trial, researchers identified a collection of 15 genes whose expression pattern predicted the relative risk of death in people with early-stage non-small cell lung cancer (NSCLC). Now, a new study has confirmed these findings in a larger, independent group of patients. Early-stage NSCLC patients who were classified into high- or low-risk groups based on testing the expression of the 15 genes differed significantly in their overall 5-year survival. These gene expression patterns may therefore help distinguish patients at higher risk who would benefit from adjuvant chemotherapy (chemotherapy given after tumor removal surgery), from lower-risk patients who could avoid the side effects of chemotherapy. Indeed, the Pervenio test, which looks at the expression of 14 genes, is already used to identify the patient who may benefit from aduvant chemotherapy.