Both Aβ and Tau promote cofilin–actin pathology,4, 5 cofilin–actin pathology is widespread in AD brains,6 and cofilin activity is also increased in AD brains.7 Cofilin normally functions as a key regulator of actin dynamics that destabilizes filamentous actin (F-actin). This evidence concerns the gene CFL1 and Alzheimer disease.