CD300e: Emerging role and mechanism as an immune-activating receptor

•CD300e functioned as an immune-activating receptor.•Dysfunction of CD300e was associated with various pathophysiological processes.•CD300e regulated inflammation and autoimmunity through complicated mechanisms.•CD300e was a diagnostic and therapeutic target for infections and autoimmune disorders. As a transmembrane protein, CD300e is primarily expressed in myeloid cells. It belongs to the CD300 glycoprotein family, functioning as an immune-activating receptor. Dysfunction of CD300e has been suggested in many diseases, such as infections, immune disorders, obesity, and diabetes, signifying its potential as a key biomarker for disease diagnosis and treatment. This review is aimed to explore the roles and potential mechanisms of CD300e in regulating oxidative stress, immune cell activation, tissue damage and repair, and lipid metabolism, shedding light on its role as a diagnostic marker or a therapeutic target, particularly for infections and autoimmune disorders.