Serologies were negative for SLE or other autoimmune conditions, including a negative work-up for antinuclear antibodies (ANA), antineutrophil cytoplasmic antibodies, C3/C4, anti-double-stranded DNA, anti-Smith, phospholipase A2 receptor, thrombospondin type-1 domain-containing 7A, and cryoglobulins. This evidence concerns the gene C3 and systemic lupus erythematosus.