Predicted to enable MHC class I protein binding activity and coreceptor activity. Predicted to be involved in regulation of immune response. Predicted to act upstream of or within adaptive immune response. Located in external side of plasma membrane. Is expressed in several structures, including alimentary system; endocrine gland; hemolymphoid system gland; liver and biliary system; and reproductive system. Orthologous to several human genes including CD8B (CD8b molecule). [provided by Alliance of Genome Resources, Apr 2022]