The amount of a serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform (human) when measured in cerebrospinal fluid. The trait is level of serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform (human) in cerebrospinal fluid (OBA_2057610). Also known as: cerebrospinal fluid serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform (human) amount.