Serum biomarkers have already been used for tumor diagnosis (early detection with assessment of the primary site), prognosis (stage, progression of the tumor, resistance to drugs) and monitoring (recurrence of the tumor), e.g., BRAF mutations found in patients with melanoma, exon 11 KIT mutations in GISTs, etc. Liquid biopsies also have a potential role in personalized medicine. The gene discussed is BRAF; the disease is neoplasm.