SLE: systemic lupus erythematosus, SLEDAI: Systemic Lupus Erythematosus Disease Activity Index, C3: complement 3, C4: complement 4, anti-dsDNA: anti-double-stranded DNA, Th10 cells: T helper 10 cells, IL-10: interleukin 10. Here, C4A is linked to systemic lupus erythematosus.