These results are consistent with those of Yeh et al (2002) and Cui et al (2001) who could not detect mutations or loss of CTCF mRNA in Wilms' tumours and with those of Aulmann et al (2003) who used immunohistochemistry, allelic studies and mutation screen of the CTCF gene and did not find loss of CTCF protein expression in invasive ductal carcinoma of the breast. The gene discussed is CTCF; the disease is invasive ductal breast carcinoma.