Some authors have previously suggested that the envelope protein is capable of modifying the vascular permeability of the endothelium, either directly, altering the morphology of endothelial cells,57 or through the infection of monocytes, which, in turn, contribute to viral replication and production of nitric oxide and cytokines, and, consequently, to an increase in endothelial permeability.58 This evidence concerns the gene ERVW-1 and infection.