This significant decrease in IL-6 promoter activity caused by calpain inhibition is consistent with a study performed in PBMC obtained from heathy or multiple-sclerosis donors that demonstrated a decrease in IL-6 mRNA in PBMC pre-treated with a calpain inhibitor and stimulated with anti-CD3/CD28 [60], suggesting that calpain could be involved in IL-6 production induced by different stimuli. Here, CD28 is linked to multiple sclerosis.