B cell CLL/leukemia 10 (Bcl-10), a 233 amino acid, 26.2kD protein, is the cellular homolog of the equine Herpes virus-2 gene (E10). Bcl-10 is also known as CARD like apoptotic protein (CLAP), CED-3/ICH-1 prodomain homologous E10-like regulator (CIPER), celluar-E10 (c-E10), and CARD-containing molecule enhancing NFkappaB (CARMEN). Bcl-10 contains a caspase recruitment domain (CARD) and has been shown to induce apoptosis and to activate NF-kappaB. Bcl-10 can interact with other CARD domain containing proteins including CARD9, 10, 11, and 14, which function as upstream regulators of NF-kappaB signaling. Defects in Bcl-10 may be involved in the pathogenesis of human malignancy.