We found HER-2/TOPOIIα gene amplification/protein overexpression and chromosome 17 aneusomy (polysomy) in a high proportion of patients with dysplasia (LGD and HGD) or ADC, but in almost none of the patients with BO, suggesting involvement of these factors in cancer development. The gene discussed is ERBB2; the disease is bronchiolitis obliterans syndrome.