The amount of a serine protease inhibitor Kazal-type 4 (human) when measured in cerebrospinal fluid. The trait is level of serine protease inhibitor Kazal-type 4 (human) in cerebrospinal fluid (OBA_2056257, an Ontology of Biological Attributes identifier). Also known as: cerebrospinal fluid serine protease inhibitor Kazal-type 4 (human) amount.