S100B and infection: Nonetheless, the fact that SIVden relies essentially on Vpu for activity on tetherin, and the fact that this effect on C. denti tetherin is clearly stronger than that of SIVdeb Nef on C. neglectus tetherin, together suggest that during infection of C. denti, SIVden may be confronted to higher levels of tetherin expression than those in SIVdeb-infected C. neglectus monkeys.