One AD-enriched tau cleavage region (Q244/T245), the calpain 1 cleavage site favored in oligomeric tau in vitro, is in close vicinity to the previously reported R242 truncation16, which generates a 24 kDa band that increases with age in mice overexpressing human tau, and has higher aggregation and seeding activity than full length tau in vitro16. The gene discussed is CAPN1; the disease is Alzheimer disease.