MTC is characterized by RET gene abnormalities in 60-90% of cases, making it highly responsive to RET-targeted therapies, which significantly improve prognosis [8]. This is particularly relevant in high-grade MTC, which constitutes approximately 25% of cases and is associated with significantly poorer outcomes compared to low-grade MTC, with 10-year overall survival rates of only 47% versus 91% [9]. The identification of RET mutations in high-grade tumors may, therefore, have critical prognostic and therapeutic implications. The gene discussed is RET; the disease is medullary thyroid gland carcinoma.