To this end, we overexpressed ERβ1 and ERβ5 in EGFR exon 19 deletion-harboring lung adenocarcinoma cells and assessed their ability to form heterodimers, as well as the relevance of ERβ1/ERβ5 heterodimerization in non-genomic signaling and response to EGFR TKIs. This evidence concerns the gene EGFR and lung adenocarcinoma.