Selective deletion of CTLA-4 in Tregs of BALB/c mice results in fatal T-cell-mediated autoimmune disease at just 20 days of age.76 Additionally, several cases of germline heterozygous mutations in CTLA-4 have been identified in humans.77 CTLA-4 haploinsufficiency resulted in dysregulation of Tregs, hyperactivation of Teffs and lymphocytic infiltration of target organs including the GI tract. The gene discussed is CTLA4; the disease is autoimmune disease.