The aims of our investigation are to determine: (1) if HPV types 16, 18 and 33 gene sequences (the most common HPV carcinogens in cervical cancer) are present in breast cancers that have occurred in predominantly Caucasian Australian women, and (2) if there are any correlations between the presence of HPV sequences and grade of tumour, patient mortality, hormone receptor status, abnormal p53 protein expression, the presence of p53 mutations and ERB-2 expression. The gene discussed is NR4A1; the disease is breast carcinoma.