The bibliographic prospection revealed that in Ecuador leishmaniasis is mainly produced by 4 species of Leishmania: L. braziliensis, L. panamensis, L. amazonensis and L. mexicana, and the most relevant targets for leishmaniasis expressed by them are: Dihydrofolate reductase-thymidylate synthase (DHFR-TS); Pteridine Reductase 1 (PTR1); Pyruvate kinase (PK); Hypoxanthine-guanine phosphoribosyltransferase (HGPRT); Cysteine proteases (CP); Superoxide dismutases (SOD); Inositol phosphorylceramide synthase (IPCS) and Squalene synthase (SQS) [25,26,27,28]. This evidence concerns the gene TYMS and leishmaniasis.