The reasons for not detecting other known prevalent emerging mutations such as EGFR (ECD) in this study are unclear, but could be related to the relative limited genomic heterogeneity and tumor burden in first-line (this study) compared to later lines of treatment as EGFR ECD mutations are thought to take typically longer than KRAS mutations to emerge17 and are not likely to be founding clonal events3,4. The gene discussed is EGFR; the disease is neoplasm.