SWI/SNF-related matri, Xenopus/Amphibian,-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1) is an ATP-dependent chromatin-remodeling comple, Xenopus/Amphibian, that plays important roles in cell proliferation and differentiation, in cellular antiviral activities and inhibition of tumor formation. Defects in SMARCB1 are a cause of schwannomatosis (SCHWA), also called congenital cutaneous neurilemmomatosis. Schwannomas are benign tumors of the peripheral nerve sheath that usually occur singly in otherwise normal individuals.