CCL2 and keratoconus: We also evaluated the effect of TLR4 knockdown to 7-KC-induced inflammation in peritoneal macrophages using siRNA transfection, and showed that TLR4 knockdown did not influence 7-KC-induced MCP-1 or TNF-α expression (Fig. S6C), excluding a role for TLR4 in 7-KC-induced inflammation in macrophages.