Tafenoquine and primaquine are recommended by the World Health Organization (WHO) for the treatment of relapsed malaria owing to its efficiency of eradicating the hypnozoites of P. vivax via 5-hydroxy-primaquine (5-hydroxy-primaquine) formed by the enzyme CYP2D6 (Cytochrome P450, family 2, subfamily D, polypeptide 6) in human liver cells [9–12]. Here, CYP2D6 is linked to malaria.