To guide the literature selection, we used the following inclusion criteria: (1) articles published in peer-reviewed journals, (2) studies focusing on fibrinolytic components (e.g., plasmin, PAI-1, uPA/uPAR, α2-antiplasmin) in the context of autoimmune diseases, and (3) both original research and review articles that provide mechanistic insights or clinical relevance. The gene discussed is SERPINE1; the disease is autoimmune disease.