Signosis EL-017 is a CHO stable cell line expressing EGFR with the T790M mutation arising from c.2369C>T in exon 20. The cell line was generated using an MSCV-IRES-EGFP retroviral construct with GFP-based selection by FACS and validated via PCR sequencing and Western blot. It enables studies on tumor susceptibility and screening of EGFR TKIs such as gefitinib and erlotinib.