In this study, relationships between serum levels of BDNF and some main gene polymorphisms of both BDNF (Val66Met, rs6265; C270T, rs56164415) and molecules potentially involved in inflammation (IL-1 family, including IL-1α rs1800587; IL-1β rs1143627; IL-38 rs6743376), in oxidative stress and mitochondrial damage or protection (APOE rs7412 and rs429358, FOXO3A rs2802292, SIRT3 rs11555236, GLO1 rs1049346 and SOD2 rs4880) were investigated in patients affected by AD or MCI, to determine potential predictive risk associations. The gene discussed is FOXO3; the disease is Alzheimer disease.