TYMS and leishmaniasis: Research conducted by Nare et al. to investigate new chemotherapy for Leishmaniasis by reviewing the literature on the advancement of the metabolism of pteridines in Leishmania revealed that Pteridine reductase, an enzyme expressed by these auxotrophs, is responsible for the folate reduction and growing resistance to antifolates by the dihydrofolate reductase and thymidylate synthase (DHFR-TS) complex [29].