Accordingly, pancreatic adenocarcinoma samples showed reduced syncytin-1 expression concomitant to ERVWE1 LTRs hypermethylation (Lu et al., 2015), and B16F10 melanoma cells stably expressing syncytin-1 were significantly limited in proliferation and invasion (Mo et al., 2013). This evidence concerns the gene ERVW-1 and melanoma.