However, we found that anti-Scl-70 autoantibody and C3 levels were not correlated, suggesting that anti-Scl-70 autoantibodies could induce endothelial alterations via other mechanisms than the fixation and activation of the complement cascade, such as antibody-dependent cell-mediated cytotoxicity, which has already been described in SSc in the case of anti-endothelial cell autoantibodies [31,32,33]. Here, C3 is linked to systemic sclerosis.