Taken together, our findings demonstrate that six lines all coming from thoracic malignancies and previously designated as SCLC, harbor SMARCA4 mutations and display histologic, and a lack of neuroendocrine features, consistent with either SMARCA4-deficient NSCLC or thoracic SMARCA4-UT rather than SCLC. This evidence concerns the gene SMARCA4 and non-small cell lung carcinoma.