ROS1 and lung adenocarcinoma: Around the same time, a transformation assay with a cDNA expression library (not genomic libraries [17]) from a lung adenocarcinoma sample led to the discovery of EML4-ALK fusions [10], and a high-throughput phosphotyrosine signaling screen of lung cancer cell lines and tumors identified SLC34A2-ROS1 fusions in non-small-cell lung carcinoma (NSCLC) [9].