CD33 and Alzheimer disease: Compared to WT mice, APP/PS1 mice exhibited higher levels of Iba1 (p < 0.05), GFAP (p < 0.01), arachidonate 5-lipoxygenase (ALOX5) (an enzyme that participates in AD-related neuroinflammation by enhancing Iba1 and GFAP 39; p < 0.001), myeloid cell surface antigen CD33 (CD33) (a transmembrane sialic acid-binding receptor located on the surface of microglia that promotes Aβ pathology 40; p < 0.05), and inducible nitric oxide synthase (iNOS) (an enzyme that produces NO which can be toxic to neurons and is upregulated in the brains of patients with AD 37; p < 0.001) (Fig. 5J and Fig. S5E).