Microglia activation is one of the first sign of prion disease and is characterized by increased expression of the anti-inflammatory cytokines, such as transforming growth factor-beta (TGF-β) and prostaglandin E2 (PGE2), and signaling receptors, such as triggering receptor myeloid 2 cells (TREM2), sialic acid binding Ig-like lectin F (SiglecF), cell surface transmembrane glycoprotein CD200 receptor 1(CD200R), and fragment crystallizable gamma receptor (Fcg) [61,62]. The gene discussed is CD200R1; the disease is prion disease.