Four cell lines, lung cancer PC9 cells (EGFRL858R+ and FGFR1−), lung cancer H520 cells (EGFR− and FGFR1+), lung cancer H1975 cells (EGFRL858R/T790M+ and FGFR1+), and normal lung epithelial cells Beas-2B cells (EGFR+ and FGFR1+), were chosen for the cytotoxic assay (Figure 1C). Here, EGFR is linked to lung cancer.