Enables complement binding activity. Predicted to be involved in complement activation, classical pathway; cytolysis; and innate immune response. Predicted to act upstream of or within complement activation. Located in extracellular space. Biomarker of myocardial infarction. Human ortholog(s) of this gene implicated in type I complement component 8 deficiency. Orthologous to human C8A (complement C8 alpha chain). [provided by Alliance of Genome Resources, Apr 2022]