In the 2023 Clinical Practice Guideline for metastatic NSCLC of the European Society of Medical Oncology (ESMO), predictive testing is recommended for biomarkers in 11 genes (EGFR, KRAS G12C, BRAF V600, MET exon 14 skipping, ERBB2, ALK, ROS1, RET, NTRK1/2/3) and for each biomarker at least one targeted therapy is recommended in the first or second line of therapy.9 The gene discussed is ROS1; the disease is non-small cell lung carcinoma.