Given that the *10/*10 genotype still accounted for the largest proportion (30.3%) in the overall study cohort and the no-function *4/*4 genotype was found in the SR group [39], the risk of declined therapeutic efficacy of primaquine caused by defective CYP2D6 enzyme activity in malaria endemic areas should not be ignored. The gene discussed is CYP2D6; the disease is malaria.