#complement.enzyme  one of a series of enzymes in the blood serum that are part of the immune response
  supertype:  enzyme  any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions
  part of:  immune_response__immune_reaction__immunologic_response__immunologicresponse  a bodily defense reaction that recognizes an invading substance (an antigen: such as a virus or fungus or bacteria or transplanted organ) and produces antibodies specific against that antigen

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