Among patients with AF, 926 received DOACs therapy at hospital discharge; cystatin-C was not measured in 85 of them, thus all the eGFR formulas were available in 841 patients (mean age 85.9 ± 6.5 years, 59.2% women): 287 (34.1%) received rivaroxaban, 278 (33.0%) apixaban, 252 (30.0%) dabigatran and 24 (2.9%) edoxaban. The gene discussed is CST3; the disease is atrial fibrillation.