Mice infected with Toxoplasma gondii associated with the administration of subdoses of Aβ peptide presented significant impairments in learning and memory functions and increased IL-1β, TNF-α, IFN-γ, and inducible nitric oxide synthase (iNOS) mRNA levels, similar to the Alzheimer’s disease group, which received high doses of Aβ but were not infected (Mahmoudvand et al., 2016). This evidence concerns the gene NOS2 and early-onset autosomal dominant Alzheimer disease.