Interestingly, the LOH at the 11q13 region is observed in the majority of MEN1 parathyroid tumors, while it is less frequent in the sporadic counterpart, confirming the role of an inactivation of an 11q13-located tumor suppressor gene (TSG) in parathyroid tumorigenesis, but also highlighting an apparent heterogeneity within sporadic parathyroid tumors [38]. The gene discussed is MEN1; the disease is tumor of parathyroid gland.