We could not detect folate receptor 1 (FOLR1) in the mouse brain; however, it is known that this GPI-AP expresses on the choroid plexus epithelium being involved in the transcytosis of 5-methyl tetrahydrofolate (5MTHF) from blood to cerebrospinal fluid (CSF) and decreased expression of FOLR1 causes cerebral folate deficiency.27 This evidence concerns the gene FOLR1 and neurodegenerative syndrome due to cerebral folate transport deficiency.