Whilst in the EPIC-CAD trial,8 edoxaban was used at the approved dose, also for Asian populations, of 60 mg once daily (OD), to be reduced to 30 mg OD in the presence of creatinine clearance (CrCl) <50 mL/min or body weight <60 kg or concomitant P-glycoprotein inhibitor treatment, in the AFIRE trial7 the doses of rivaroxaban were the ones tested in the J-ROCKET AF trial,10 and approved for Japanese patients,11 i.e. 15 mg OD, to be reduced to 10 mg OD when CrCl was <50 mL/min, instead of the 20/15 mg OD regime tested in the international ROCKET AF trial. Here, ABCB1 is linked to atrial fibrillation.