An ongoing clinical trial is evaluating the effects of cancer drug tivantinib in non-small cell lung cancer (NSCLC). The trial studies patients with advanced non-squamous NSCLC who do not have any mutations in the EGFR gene. Patients receive erlotinib (Tarceva) either by itself or in combination with tivantinib. Enrollment in the trial was stopped because rates of interstitial lung disease (ILD), which can cause lung scarring, may be higher in patients receiving tivantinib. (No such increased levels of ILD were seen in a different trial using tivantinib.) For the patients already enrolled, overall survival, time without cancer worsening, and percentage of patients experiencing tumor shrinkage all seem increased in tivantinib-treated patients. However, it is not yet clear whether these effects are indeed caused by tivantinib or are due to chance.