CYLD and adnexal spiradenoma/cylindroma of a sweat gland: For instance, Brooke–Spiegler syndrome, caused by mutations within CYLD—a tumor-suppressor gene regulating NF-κB activation—is an autosomal-dominant disorder characterized by multiple benign cutaneous adnexal tumors (most commonly spiradenomas, cylindromas, and trichoepitheliomas [40].