MAPK14 and systemic lupus erythematosus: Furthermore, statins were noted to inhibit the production of IFN-α and TNF-α by PDCs in SLE patients, via its effect on several pathways [81], including reduction in synthesis of mevalonate (the downstream metabolite of HMG-CoA) and inhibition of CpG-induced phospho-p38 mitogen-activated protein kinase (MAPK) expression.