The process by which foamy viruses enter a cell lacks certain levels of characterization, however it is known that the virus particle first attaches to its host using the SU glycoprotein present on its envelope. The binding receptor for foamy viruses is not entirely know, however it is known that the virus is capable of infecting a board spectrum of cells, meaning the binding receptor must be quite prevalent in most forms of cells. Research has shown that the most likely candidate for a common receptor is heparan sulfate (HS), an extremely common glycosaminoglycan (GAG) present on the ECM of many cells.
