It is approved in the United States for treatment of adult patients with metastatic RET fusion-positive non-small cell lung cancer (NSCLC) and adults and pediatric patients 12 years and older with advanced or metastatic RET fusion-positive thyroid cancer who require systemic therapy and who are radioactive iodine-refractory [2,3]. The gene discussed is RET; the disease is non-small cell lung carcinoma.