ROS1 and non-small cell lung carcinoma: With reference to non-squamous NSCLC arising in Western patients, KRAS (Kirsten rat sarcoma viral oncogene homolog) gene mutations can be found in about 10–15% of patients, EGFR (epidermal growth factor receptor) in approximately 10–15%, ALK (anaplastic lymphoma kinase) in 3–5%, BRAF (v-raf murine sarcoma viral oncogene homolog B1) in 2–3%, ROS1 (c-ros oncogene 1) in 1–2%, RET (rearranged during transfection) in 1–2%, MET (MET proto-oncogene) in 1–2%, and NTRK (neurotrophic receptor tyrosine kinase 1) in 0.1–1% of patients [18,19,20,21,22].