SLC46A1 and neoplasm: The proton-coupled folate transporter (PCFT/SLC46A1) has recently emerged for its key role in folate and antifolate transport, which was demonstrated in various model systems, including MPM,9 and in several human tissues.10 Of note, the activities of the folate transporters reduced folate carrier (RFC/SLC19A1), and PCFT is significantly affected by the pH of the tumour microenvironment (TME).