Selpercatinib (53) and pralsetinib (54) are the latest approved TKIs by the FDA, occurring respectively in May 2020 and December 2020; these two drugs are indicated for the treatment of RET-fusion RAI-R DTC and the treatment of RET-mutant MTC in patients aged ≥12 years. The gene discussed is RET; the disease is medullary thyroid gland carcinoma.