This chapter focuses on the biology of the major facilitative membrane folate transporters,
the reduced folate carrier (RFC), and the proton-coupled folate transporter (PCFT). Folates
are essential vitamins, and folate deficiency contributes to a variety of heath disorders. RFC
is ubiquitously expressed and is the major folate transporter in mammalian cells and tissues.
PCFT mediates intestinal absorption of dietary folates. Clinically relevant antifolates such as
methotrexate (MTX) are transported by RFC, and the loss of RFC transport is an important …