Importantly, compared with CYLD-wildtype AC, CYLD-mutant AC showed over ninefold higher frequency of cylindroma-like histology, as principally designated by the presence of basement membrane inclusions within tumor cell aggregates (73% vs. 8%, p < 0.0001; Table 1). The gene discussed is CYLD; the disease is adnexal spiradenoma/cylindroma of a sweat gland.