ROS1
[5][6] This proto-oncogene, highly expressed in a variety of tumor cell lines, belongs to the sevenless subfamily of tyrosine kinase insulin receptor genes.[7][11] In 2016, the small molecule tyrosine kinase inhibitor, crizotinib, was approved for the treatment of patients with metastatic NSCLC whose tumors are ROS1 -positive.[19][20] Preclinical and clinical work suggests multiple potential mechanisms of drug resistance in ROS1 + lung cancer, including kinase domain mutations in ROS1 and bypass signaling via RAS and EGFR.[11] Similar findings were reported in a separate analysis of 447 NSCLC samples, of which 1.2% were found to be positive for ROS1 rearrangement; this study also confirmed the activity of the ALK/ROS1 /cMET inhibitor crizotinib in ROS1 -positive tumors.* Multiple variant isoforms observed CD74; cluster of differentiation 74, long/short isoforms; EZR; ezrin; FIG; fused in glioblastoma; SDC4; LRIG3; leucine-rich repeats and immunoglobulin-like domains 3; SDC; syndecan 4; SLC34A2; solute carrier family 34 (sodium phosphate), member 2; TPM3; tropomyosin 3 Several drugs target ROS1 fusions in cancer, with varying levels of success; most of the drugs to date have been tested only for ROS1-positive non-small cell lung carcinoma (NSCLC).