The amount of a PC(17:0_20:4) when measured in blood serum. The trait is Ontology of Biological Attributes identifier OBA_2045087 (level of Phosphatidylcholine (17:0_20:4) in blood serum). Also known as: blood serum PC(17:0_20:4) amount, level of PC(17:0_20:4) in blood serum.