It is the first drug to be approved for the treatment of adult patients with metastatic MTC by the FDA.160 However, this indication is most likely attributed to its inhibitory effect on RET, a tyrosine kinase hyperactivated by mutations in MTC.161 Another anti-angiogenic inhibitor used for the clinical treatment of MTC is cabozantinib, which also has high RET inhibitory activity.162 Relatedly, the FDA-approved two highly specific RET inhibitors (selpercatinib and pralsetinib) in 2020. This evidence concerns the gene RET and medullary thyroid gland carcinoma.