To investigate the role of systemic infection further in Alzheimer’s cases, we used TaqMan qPCR to compare the fold difference in mRNA levels between AD+ and AD- cases for cytokines and cytokine receptors (IL1b, IL4R, IL6, IL10, IFNg, TNF, TGFb1), enzymes (ARG1, COX2, NOS2), receptors (CD86, CD163, CD206, TREM2,) and the anti-inflammatory marker CHI3L1 (Chitinase 3-Like 1), relative to GAPDH mRNA. The gene discussed is CHI3L1; the disease is Alzheimer disease.