RET and medullary thyroid gland carcinoma: Both the ARROW and Libretto-001 trials showed that pralsetinib and selpercatinib efficacy was irrespective to prior multi-TKI treatment, giving an indirect proof of the clinical activity of these drugs towards the RET gatekeeper mutations potentially occurring after this prior treatment (detected only in patients with medullary thyroid carcinoma) [62,75].