In parallel, a study by Bell et al. (2009) reported that hypoxia also causes the impairment of brain clearance of Aβ through stimulation of serum response factor (SRF) and myocardin (MYOCD) expressions [91], which were found to be much more active in the blood vessels of brains of people with AD than in people who do not have the disease [92]. This evidence concerns the gene SRF and Alzheimer disease.