ERBB2 and non-small cell lung carcinoma: Our ctDNA CNV pipeline application would highly benefit in late stage non-small cell lung cancer patients when tissue biopsy is not available, especially in EGFR TKI resistant patients, where EGFR, ERBB2 and MET can account for 20%~40% patient population and no effective liquid biopsy assay to identify the resistant mechanism and following treatment decision.