Acts as a negative regulator of the Wnt signaling pathway required for anterior neural structure formation (By similarity). Binds preferentially to DNA containing cytidine-phosphate-guanosine (CpG) dinucleotides over CpH (H=A, T, and C), hemimethylated-CpG and hemimethylated-hydroxymethyl-CpG (By similarity). The CXXC zinc finger mediates binding to CpG-DNA.