MALT1(Mucosa-associated lymphoid tissue lymphoma translocation protein 1), also called MLT or PARACASPASE, is a protein that in humans is encoded by the MALT1 gene. This gene has been found to be recurrently rearranged in chromosomal translocation with two other genes - baculoviral IAP repeat-containing protein 3 (also known as apoptosis inhibitor 2) and immunoglobulin heavy chain locus - in mucosa-associated lymphoid tissue lymphomas. Dierlamm et al. (1999) and Akagi et al. (1999) mapped the MALT1 gene to chromosome 18q21. Using mouse models, Ruland et al. (2003) demonstrated that MALT1 is essential for T-cell activation, proliferation, and IL2 production in response to T-cell receptor ligation and strictly required for signal-specific NF-kappa-B (NFKB) activation induced by the T-cell receptor but not TNF-alpha or IL1 signaling. MALT1 operates downstream of BCL10, controls the catalytic activity of the canonical I-kappa-B kinase complex, and regulates the signaling of JNK and p38 MAP kinases.