Importantly, we observed for the first time diversified relationships between AA levels and the main factors of the fibrinolytic system—a positive correlation was observed between AA and uPA/suPAR in the mild-to-moderate CKD subgroup, whereas an inverse relationship existed between AA and tPA/PAI-1 in the severe-to-end-stage CKD subgroup. The gene discussed is SERPINE1; the disease is chronic kidney disease.