Decreased 4-1BB expression on HIV-specific CD4+ T cells is associated with sustained viral replication and reduced IL-2 production.
Kassu A, D'Souza M, O'Connor BP, Kelly-McKnight E, Akkina R, Fontenot AP, Palmer BE. Decreased 4-1BB expression on HIV-specific CD4+ T cells is associated with sustained viral replication and reduced IL-2 production. Clin Immunol. 2009 Aug; 132(2):234-45.