Actually, trastuzumab (HerceptinR), a humanised monoclonal antibody that recognises the HER-2/Neu protein receptor, is under investigation for the treatment of lung cancers overexpressing HER-2/Neu, but the choice of the method of detection and the level of Her-2/Neu expression required to obtain a potential therapeutic effect from trastuzumab therapy have not yet been established in lung cancer. Here, ERBB2 is linked to lung cancer.