Based on efficacy data from clinical trials, two highly selective RET inhibitors selpercatinib and pralsetinib were approved by the FDA in the year 2020 for treating patients with metastatic RET fusion-positive non-small cell lung cancer (NSCLC), advanced or metastatic RET-mutant MTC and advanced or metastatic RET fusion-positive thyroid cancer [16–19]. The gene discussed is RET; the disease is thyroid cancer.