Essential for normal retinal maturation and development (By similarity).Acts as a retinal cell surface receptor for NXNL1 and plays an important role in NXNL1-mediated survival of retinal cone photoreceptors (PubMed:25957687).In association with glucose transporter SLC16A1/GLUT1 and NXNL1, promotes retinal cone survival by enhancing aerobic glycolysis and accelerating the entry of glucose into photoreceptors (PubMed:25957687).May act as a potent stimulator of IL6 secretion in multiple cell lines that include monocytes (PubMed:21620857).