As grouped in Table 1, over- expression of HER-2/neu was detected in only 40.43% of those with pure invasive ductal carcinomas (Figure 1), in comparison with 77.68% of invasive ductal carcinoma with an in situ comedo component (DCIS), in 100% of invasive ductal carcinoma with overlying Paget's disease and in 100% of purely DCIS (Figure 2) and that with overlying Paget's disease. This evidence concerns the gene ERBB2 and invasive ductal breast carcinoma.