In a small group of patients with amnestic mild cognitive impairment and Alzheimer's disease, the presence of IL-33 is associated with better cognitive function over a year, while the levels of Aβ, tau, and apolipoprotein E-ε4 (a genotype known to associated with cognitive decline) are comparable between patients expressing and those not expressing IL-33 [156]. The gene discussed is IL33; the disease is early-onset autosomal dominant Alzheimer disease.