Folate receptor 1 (Folate receptor alpha, FOLR1) is a protein that in humans is encoded by the FOLR1 gene. The protein encoded by this gene is a member of the folate receptor (FOLR) family. Members of this family have a high affinity for folic acid and for several reduced folic acid derivatives, and mediate delivery of 5-methyltetrahydrofolate to the interior of cells. This gene is composed of 7 exons; exons 1 through 4 encode the 5' UTR and exons 4 through 7 encode the open reading frame. Due to the presence of 2 promoters, multiple transcription start sites, and alternative splicing of exons, several transcript variants are derived from this gene. These variants differ in the lengths of 5' and 3' UTR, but they encode an identical amino acid sequence. FRA can be overexpressed by a number of epithelial-derived tumors including ovarian, breast, renal, lung, colorectal, and brain. Hence antibodies to it are used in targeted therapies and diagnostic tests, e.g. farletuzumab in phase III trial for ovarian cancer. Autoantibodies to the FRA have been linked to neurodevelopmental diseases, particularly cerebral folate deficiency schizophrenia and autism spectrum disorder. Recent studies have shown that these neurodevelopmental disorders can be treated with folinic acid.