Interacts with zinc finger protein A20/TNFAIP3 and inhibits TNF-induced NF-kappa-B-dependent gene expression by interfering with an RIP-or TRAF2-mediated transactivation signal (By similarity). Increases cell surface CD4(T4) antigen expression. Interacts with HIV-1 matrix protein and is packaged into virions and overexpression can inhibit viral replication. May regulate matrix nuclear localization, both nuclear import of PIC (Preintegration complex) and export of GAG polyprotein and viral genomic RNA during virion production.Synonyms: HIV-1 Nef-interacting protein, KIAA0113, NAF1, Nef-associated factor 1, Nip40-1, TNFAIP3-interacting protein 1, VAN, Virion-associated nuclear shuttling protein