To further understand the relationship between TKI sensitivity and deregulation of EGFR pathway genes, we examined the mutation and copy number status of seven of these genes (EGFR, HER2, HER3, HER4, KRAS, BRAF, and PIK3CA) in a large panel of lung cancer cell lines and correlated the data with in vitro sensitivity to TKIs. Here, EGFR is linked to lung cancer.