Early-stage non-small cell lung cancer (NSCLC) is usually treated with surgical removal of the tumor. However, in up to 50% of patients, the cancer will return within 5 years. A study of genetic variations that affect the function of microRNAs (small molecules involved in gene expression) found that several of them, including variations in the FAS, FZD4, SP1, and DROSHA genes, were associated with higher or lower probabilities of cancer recurrence and survival. Tests for such microRNA-related genetic variations may eventually help identify high-risk, early-stage NSCLC patients who would benefit from additional treatment after surgery.