The rheumatology team conducted a comprehensive lupus workup, including tests for antinuclear antibody (ANA) enzyme-linked immunosorbent assay (ELISA), antineutrophil cytoplasmic antibodies (ANCA) proteinase 3 (PR3), ANCA myeloperoxidase (MPO), beta-2 glycoprotein antibodies, cardiolipin antibodies, complement component 3 (C3) and component 4 (C4), erythrocyte sedimentation rate (ESR), and a coagulation profile, all of which were within normal limits (Table 1). Here, C3 is linked to systemic lupus erythematosus.