SFRP1 and pancreatic neoplasm: Additionally, the loss of SFRP1 mRNA and protein expression in pancreatic cancer is significantly influenced by a core CpG island (CGI2) that covers the transcription start site and the first half of exon1 of the SFRP1 gene, which suggests that CGI2 may influence exon1 recognition through methylation of exon1 [40].