The amount of a protein phosphatase 1 regulatory subunit 3B (human) when measured in cerebrospinal fluid. The trait is level of protein phosphatase 1 regulatory subunit 3B (human) in cerebrospinal fluid (Ontology of Biological Attributes term OBA_2059617). Also known as: cerebrospinal fluid protein phosphatase 1 regulatory subunit 3B (human) amount.