P0C0L5 [Direct mapping]
Complement C4-B Complement C4 beta chain Complement C4-B alpha chain C4a anaphylatoxin C4b-B C4d-B Complement C4 gamma chain

GO:0001848 [complement binding]
GO:0004866 [endopeptidase inhibitor activity]
GO:0005515 [protein binding]
GO:0005576 [extracellular region]
GO:0005615 [extracellular space]
GO:0005886 [plasma membrane]
GO:0006954 [inflammatory response]
GO:0006956 [complement activation]
GO:0006958 [complement activation, classical pathway]
GO:0008228 [opsonization]
GO:0010951 [negative regulation of endopeptidase activity]
GO:0030246 [carbohydrate binding]
GO:0030449 [regulation of complement activation]
GO:0032490 [detection of molecule of bacterial origin]
GO:0044216 [other organism cell]
GO:0045087 [innate immune response]
GO:0070062 [extracellular exosome]
GO:0072562 [blood microparticle]
GO:2000427 [positive regulation of apoptotic cell clearance]