The present study was undertaken to investigate: (i) the role of amplification/overexpression of TOPOIIα and HER-2/neu genes and proteins, (ii) the association between TOPOIIα amplification/overexpression, HER-2/neu amplification/overexpression and chromosome 17 aneusomy, and (iii) the association between TOPOIIα and HER-2/neu amplification/overexpression and chromosome 17 aneusomy and the presence of BO, low-grade (LGD) or high-grade dysplasia (HGD) and ADC. The gene discussed is ERBB2; the disease is AIDS dementia complex.