The amount of a ribonucleoside-diphosphate reductase subunit M2 (human) when measured in cerebrospinal fluid. The trait is level of ribonucleoside-diphosphate reductase subunit M2 (human) in cerebrospinal fluid (Ontology of Biological Attributes id OBA_2057637). Also known as: cerebrospinal fluid ribonucleoside-diphosphate reductase subunit M2 (human) amount.