**4. Molecular markers of resistance to artemisinin**

Artemisinin and its derivatives are the current in-use antimalarial drug in most malaria-endemic countries. Clinical resistance to artemisinin and its derivatives has not yet been defined, but what has been reported is delayed parasite clearance in clinical isolates from Cambodia. The emergence of delayed parasite clearance to artemisinin and its derivatives calls for concerns as it may emerge into full resistance [41]. This makes it important to identify molecular markers of resistance to artemisinin and its derivatives. A molecular marker that has been suggested to cause partial resistance to artemisinin and its derivatives is the ATP-consuming calciumdependent *P. falciparum* SERCA ortholog, *Pfatp6*. The *Pfatp6* L263E mutation has been associated with increased artemisinin and dihydroartemisinin IC50 values in D10 parasite strains. Parasite clinical isolates from France with the *pfatp6* S769N mutation have been reported to have high IC50 values to artemether [42]. Another gene that has been associated with artemisinin and its derivatives is the *Kelch 13* gene. The *kelch 13* encodes 726 amino acids and located on chromosome 13 [43]. The kelch family of proteins has diverse functions, including organizing and interacting with other proteins. Mutations in the *Kelch 13* gene that have been associated with artemisinin resistance include Y493H, R539T, I543T, F446L, P574L, and C580Y [43, 44].
