The linearly interpolated TTR has become a widely accepted measure of the quality of anticoagulation management.7 In the ROCKET AF trial, the mean i‐TTR for patients assigned to warfarin was 55%, lower than that reported for other recent trials of novel anticoagulants,17–19 with a wide range of i‐TTR values. The gene discussed is TTR; the disease is atrial fibrillation.