Department of Laboratory Medicine Yonsei University College of Medicine Seoul 03722 South KoreaDepartment of Laboratory Medicine Gangnam Severance Hospital Yonsei University College of Medicine Seoul 06273 South Korea;
Department of Laboratory Medicine Gangnam Severance Hospital Yonsei University College of Medicine Seoul 06273 South Korea;
Center for Precision Medicine Gangnam Severance Hospital Yonsei University College of Medicine Seoul 06273 South Korea;
Division of Medical Oncology Department of Internal Medicine Gangnam Severance Hospital Yonsei University College of Medicine Seoul 06273 South Korea;
Department of Laboratory Medicine Gangnam Severance Hospital Yonsei University College of Medicine Seoul 06273 South Korea;
Gene fusion; Cell-free DNA; Liquid biopsy; Gastric cancer ; EGFR tyrosine kinase inhibitor; Case report ;