The cytoplasmic tail of the JSRV envelope protein is known to interact with host factors leading to constitutive stimulation of MAPK and PI3K/Akt signaling pathways that in turn result in activation of pro-survival and pro-proliferative pathways leading to cellular transformation and cancer (Hull and Fan, 2006; Liu and Miller, 2007). This evidence concerns the gene ERVW-1 and cancer.