Well-documented CNVs that increase risk for SLE include deletions in C4 [12] and FCGR3B [13] genes, while CNVs in other genes were associated with SLE in single-population studied, e.g., TLR7 [14], DEFB4 [15], RABGAP1L [16] and HLA-DRB5 [17]. The gene discussed is C4A; the disease is systemic lupus erythematosus.