RET and medullary thyroid gland carcinoma: In a phase 1–2 clinical trial involving adolescent and adult patients with TCs harboring an activating RET alteration (LIBRETTO 001, clinicaltrialgov NCT03157128), selpercatinib showed disease control (percentage of patients with complete response, partial response and stable disease) in more than 94% of patients with RET-mutant MTC (94% and 95% of patients already exposed to previous TKIs treatment and not, respectively) and 100% of patients with RET-mutated PTC at an independent and central review [42].