The +10 CC genotype of TGF-β1 gene, which affects the levels of expression of TGF-β1, is associated with depressive symptoms in AD (>5-fold risk) (Caraci et al., 2012), and an impairment of TGF-β1 signaling can promote the onset of a depressive-like phenotype in mice (Depino et al., 2011). Here, TGFB1 is linked to Alzheimer disease.