From the eleven human lung cancer cell lines we examined, including adenocarcinoma (Ad), squamous cell carcinoma (Sq) and large cell carcinoma (La), we found that H522 cells express Her2 at a very high level, while this cell line expresses only a small amount of Her3 and no detectable amount of EGFR (Fig. 2A). Here, EGFR is linked to squamous cell carcinoma.