ERVW-1 and hemangioma: Interestingly, JSRV Env has been shown to transform cultured fibroblasts from mice, rats, and chickens [4-6], and transformation is accompanied by activation of PI3K and Akt in these cells [8,40,41], suggesting that JSRV Env may induce hemangioma formation by activation of the PI3K-Akt-VEGF pathway in mouse endothelial cells.