In the AD group, the levels of t-Tau, Aβ1–40, Aβ1–42, α-Syn, t-Tau/Aβ1–42 ratio, Aβ1–42/ Aβ1–40 ratio, IL-1β, IL-2, IL-5, IL-10, FGF, GM-CSF, INFγ, MCP1, MIP1α, PDGF-BB, RANTES, IL-25, and IL-31 were associated with the cognitive test results. The gene discussed is IL2; the disease is Alzheimer disease.