Lung cancers express variable levels of Notch family members and ligands and the complicated interplay between the different Notch receptor and ligand family members in different tumors may underlie the observed variable in vitro efficacy of pan-Notch inhibitors such as GSIs, and the fact that the clinical trials using pan-Notch inhibitors with EGFR TKIs in lung cancer were not successful. The gene discussed is EGFR; the disease is lung cancer.