We therefore analysed methylation and expression status of SFRP1, SFRP2, SFRP5 and DKK1. SFRP1, SFRP2, SFRP5 and DKK1 were methylated in 64, 100, 91 and 27% of the breast cancer cell lines tested, respectively. This evidence concerns the gene DKK1 and breast carcinoma.