48% of patients had RET mutations. PFS was prolonged with cabozantinib in patients with/without prior TKI treatment, bone metastases at baseline and hereditary/sporadic forms of MTC and those with RET mutations; in RETM918T-positive patients, PFS (HR, 0.15; 95% CI 0.08–0.28; p<0.0001) and OS (44.3 vs 18.9 mo [HR, 95% CI: 0.60, 0.38–0.94; p=0.03) were improved with cabozantinib. The gene discussed is RET; the disease is medullary thyroid gland carcinoma.