Importantly, inhibition of MMP‐9 activity also restored the impaired CD46‐mediated IL‐10 switching and contraction of Th1 cells observed in SLE by increasing IL‐10 production significantly and tipping the IFN‐γ to IL‐10 level ratio back towards IL‐10 (Fig. 5E). The gene discussed is MMP9; the disease is systemic lupus erythematosus.