The choroid plexus--two-way traffic?
D002552:Cerebral Ventricles / Q000378:metabolism; D002555:Cerebrospinal Fluid / Q000378:metabolism*; D002831:Choroid Plexus / Q000378:metabolism* / Q000601:surgery; D006801:Humans; D006849:Hydrocephalus / Q000378:metabolism*; D007223:Infant; D012711:Serum Albumin, Radio-Iodinated
D012711:Serum Albumin, Radio-Iodinated