Based on the structures of apo-PfFNT and PfFNT-MMV007839, we propose that the PfFNT membrane protein is capable of picking up lactate ions from the parasite's cytosol, converting them to lactic acids and then exporting these acids into the extracellular space via a sequential displacement mechanism. We believe that residues lining the central channel are highly flexible and can quickly rearrange sequentially to contract and relax the channel for propelling the export of substrate across the membrane. This schematic diagram indicates that PfFNT shuttles lactate ions from the parasite's cytoplasm to the midway of the central channel. These ions will be converted to lactic acids, via proton transfer from H230, and then shuttled across the second half of the channel to the parasite's extracellular surface. Residue K35 contributes to form a transient binding site to bind lactate ion nearby to the cytoplasmic surface of the parasite. As soon as the second lactate ion arrives from the parasite's cytoplasm, the first lactate will be displaced and continue to propagate to the midway of the channel, where H230 is responsible for donating a proton to convert this lactate ion into lactic acid and open the constriction for further propagation. Residue K177 participates in forming a transient binding site, which binds lactic acid nearby the extracellular surface. A second ion enters this site will cause displacement and extrusion of lactic acid out of the parasite. 