Further, it was identified that CX3C chemokine receptor 1 (Cx3cr1), Triggering receptor expressed on myeloid cells 2 (Trem2), Spalt like transcription factor 1 (Sall1), Transmembrane protein 119 (Tmem119), Sialic-acid-binding immunoglobulin-like lectin-h (Siglec-H), Olfactomedin-like 3 (Olfml3) and P2 purinergic receptor (P2ry12) specifically expressed in microglia (Chiu et al., 2013; Galatro et al., 2017) are involved in the regulation of its physiology and could act as a possible drug target in neurodegenerative diseases. The gene discussed is TREM2; the disease is neurodegenerative disease.