Figure 2(a) shows that MCP-1 concentration was increased from basal (198 ± 21 pg ml−1) to 1357 ± 131 pg ml−1 at 72 h post-infection and such an induction could be suppressed by ER concentration dependently. As with RANTES production, Evo was the most potent in suppressing MCP-1 formation with an IC50 value of 8.7 ± 1.3 μM (Figure 2(b)). In the case of Rut, a low dose (1 and 3 μM) failed to, but a higher dose (10 and 30 μM) significantly reduced H1N1-evoked MCP-1 secretion. Here, CCL5 is linked to infection.