Coincidentally, our data showed that patients with eGFR and creatinine clearance below the cutoffs (MDRD eGFR ≤ 71 ml/min/1.73 m2; CKD-EPI eGFR ≤ 73 ml/min/1.73 m2; creatinine clearance ≤ 75 ml/min; Tables 3 and 4) have greater odds of having AF, and the cutoffs are around the level at which FGF23 is thought to rise [25]. The gene discussed is FGF23; the disease is atrial fibrillation.