Predicted to enable coreceptor activity. Involved in positive regulation of T cell proliferation. Located in cell surface. Used to study adult T-cell leukemia; anti-basement membrane glomerulonephritis; high grade glioma; and periodontal disease. Biomarker of kidney failure. Human ortholog(s) of this gene implicated in type 1 diabetes mellitus. Orthologous to human CD80 (CD80 molecule). [provided by Alliance of Genome Resources, Apr 2022]