C4A and systemic lupus erythematosus: Julkunen et al. recently found that anti-C1q and complements C3 and C4 were better markers for LN activity than anti-dsDNA antibodies; on the other hand, anti-dsDNA antibodies and serum levels of C3 and C4 were better markers than anti-C1q for evaluating the overall and non-LN SLE activity [24].