In pancreatic cancer (Lu et al. 2015), decreased syncytin-1 expression is correlated with increased DNA methylation in the 5′ LTR region of syncytin-1 promoter, and syncytin-1 expression is reactivated when methylation levels in 5′LTR are reduced (Huang et al. 2014). This evidence concerns the gene ERVW-1 and familial pancreatic carcinoma.