Anti-Dhfr antibodies are used in the immunodetection of the protein dihydrofolate reductase. In humans, the canonical protein has a reported length of 187 amino acid residues and a mass of 21.5 kDa. Its subcellular localization is in the mitochondria and cytoplasm. Alternative splicing is reported to yield 2 different isoforms for this protein. It is found to be widely expressed in fetal and adult tissues, including throughout the fetal and adult brains and whole blood. A member of a the Dihydrofolate reductase protein family, DHFR is known to be a key enzyme in folate metabolism. Synonyms for this target antigen include DHFRP1, DYR, and DHFR1.