The amount of a peptidyl-prolyl cis-trans isomerase FKBP6 when measured in blood serum. The trait is level of peptidyl-prolyl cis-trans isomerase FKBP6 in blood serum (OBA_2041591, an Ontology of Biological Attributes term). Also known as: blood serum peptidyl-prolyl cis-trans isomerase FKBP6 amount.