 Lentiviruses such as HIV-1 have acquired proteins such as Nef which perform a wide array of functions including the identification of CTLA-4 before it reaches the PM and tagging it for degradation.Nef is also known to phosphorylate and inactivate Bad, a proapoptotic member of the Bcl-2 family thus protecting the infected cells from apoptosis.Cytoskeletal remodeling is thought to reduce TCR signaling during early infection and is also modulated to some degree by Nef.