EGFR and neoplasm: Therefore, when internal low-density areas are present and primary tumors invade into surrounding tissue as observed in CT images and the tissue sample is not large enough to be submitted to tumor tissue-based test targeting multiple driver oncogene mutations, the investigation of METex14 skipping by single-plex assay such as ArcherMET may take priority over that of EGFR mutation and/or ALK rearrangement.