Deficiency or dysfunction of serpins, as in some genetic disorders, cause severe clinical disorders: antithrombin III (AT, SERPINC1), alpha‐1‐antitrypsin (A1AT, SERPINA1), complement C1 esterase‐inhibitor (C1INH, SERPING1), and neuroserpin (NSP, SERPINI1) are associated with severe clotting disorders, severe emphysema, angioedema and dementia, epilepsy, and neurodegeneration, respectively. The gene discussed is SERPINI1; the disease is dementia.