May be implicated in the establishment and/or maintenance of viral persistance. Bet is required for viral replication. Bet interacts with host APOBEC3Ca (PubMed:15911774). This interaction does not induce APOBEC3Ca degradation but prevents its dimerization and incorporation into virion (Probable). The first 31 residues are shared by isoforms Bet and Bel-1, the last 356 residues are shared by isoforms Bet and Bel-2.