MALT1 and immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome: Furthermore, MLT-943 treatment reduced Treg numbers and led to immune alterations and signs of the IPEX-like disease even in thymectomized rats, demonstrating that peripheral Treg homeostasis and function, and not just thymic Treg development, is critically dependent on MALT1 protease activity.