In this retrospective analysis for quality assessment, we surveyed our experience with clinical mutation detection of AKT1, BRAF, ERBB2, EGFR, KRAS, NRAS, and PIK3CA genes in 1006 lung cancer specimens using this NGS assay, including false negative calling, the capability of detecting complex deletion mutations within exon 19 of the EGFR gene, a high frequency of doublet (compound) EGFR mutations with concordant VAFs, and the association of kinase impaired BRAF mutations with activating RAS mutations. This evidence concerns the gene KRAS and lung cancer.