Most studies of chromosome 17q11-12 amplification have focused on the HER-2 gene such that HER-2 gene amplification and HER-2 protein over-expression have come to be recognized as important markers of clinically aggressive breast cancer and the target of specifically directed therapies (Press et al. [2008]; Goldenberg [1999]; Xia et al. [2002]). The gene discussed is ERBB2; the disease is breast cancer.