Expression of TopBP1 gene at the mRNA level was observed in 62.0 % (23/37) of poorly differentiated breast cancer (grade III), whereas nearly 80 % of tumors in I and II grade demonstrated detectable TopBP1 mRNA (78.6 % (11/14) and 78.9 % (60/76), respectively). This evidence concerns the gene TOPBP1 and breast carcinoma.