FGFR1 and adenocarcinoma: Our study in an adenocarcinoma cell line supports FGFR1 expression as an additional marker of sensitivity in accordance with previous findings.22 Including FGFR1 expression as a predictive marker for FGFR-inhibitor treatment would expand the pool of patients suitable for treatment, and would include a larger fraction of lung adenocarcinoma patients that rarely exhibit FGFR1-amplifications.