In light of our findings, which showed that PRMT5 is overexpressed in three different breast tumour cell lines, we checked if it was involved in inducing transcriptional repression of DKK1 and DKK3. ChIP analysis showed that PRMT5 binds to the promoter region of WNT antagonists, DKK1 and DKK3, and induces symmetric methylation of H3R8 and H4R3, thereby causing their transcriptional repression in HCC1937 and BT549 cells. This evidence concerns the gene DKK3 and breast neoplasm.