Studies that have addressed HER-2 as a predictive factor for hormonal therapy have demonstrated lower response rates or reduced survival in hormonally treated patients whose tumours overexpressed HER-2 (level 2+ or 3+), reaching statistical significance in most studies (Nicholson et al, 1993; Leitzel et al, 1995; Elledge et al, 1998). The gene discussed is ERBB2; the disease is neoplasm.