TLR4 and systemic sclerosis: SSc-ICs but not NHS-ICs increased ICAM-1 expression, stimulated IL-6, IL-8, MMP-2, MCP-1, TGF-β1 and Pro-CollagenIα1 secretion, upregulated et-1, ifn-α, ifn-β, tlr2, tlr3 and tlr4, and activated NFκB, p38MAPK and SAPK-JNK.