TGF-β1 is also known to be upregulated in the brain in most neurodegenerative diseases, such as PD, AD, MS, and ALS, and slow down the neurodegenerative process by preventing tissue damage and neural apoptotic death (Mogi et al., 1994; Wyss-Coray et al., 1997; Ilzecka et al., 2002; Zetterberg et al., 2004; Mirshafiey and Mohsenzadegan, 2009) so as to keep the homeostasis during disease progression. The gene discussed is TGFB1; the disease is Alzheimer disease.