Tuszynski et al. implanted modified autologous fibroblasts, whereas Eriksdotter-Jönhagen et al. implanted an NGF biodelivery device, NsG0202, into the forebrains of AD patients, and the degree of cognitive decline was significantly improved (Tuszynski et al. 2005; Eriksdotter-Jönhagen et al. 2012). This evidence concerns the gene NGF and Alzheimer disease.