They found that 3-methoxytyramine was the most accurate biomarker of metastatic disease because plasma methoxytyramine was 4.7 times higher in patients with metastases compared to patients without metastases, and high plasma methoxytyramine was associated with SDHB mutations and extra-adrenal disease, both recognized risk factors of metastatic disease. The gene discussed is SDHB; the disease is metastatic neoplasm.