The amount of a Phosphatidylethanolamine (18:0_18:2) when measured in blood serum. The trait is Ontology of Biological Attributes id OBA_2045139 (level of Phosphatidylethanolamine (18:0_18:2) in blood serum). Also known as: blood serum Phosphatidylethanolamine (18:0_18:2) amount.