The specific aim of this proposal is to study genetic polymorphism in MFG-E8, PSR and other factors implicated in phagocytic clearance of apoptotic cells among Taiwanese. By comparing the polymorphism between patients with autoimmune disease (SLE or RA) and healthy control subjects, we will investigate if genetic variations among individuals of genes encoding proteins involved in clearance of apoptotic cells contribute to the pathogenesis of systemic autoimmune diseases SLE and RA.