To further validate the proinflammatory roles of thrombin in the VSMCs, IL6 mRNA was examined by RT-qPCR.After exposure to thrombin (1, 2 or 4 U/ml), levels of IL-6 mRNA (Fig. 6A) in RA-VSMCs were increased in a dose-dependent manner. Here, IL6 is linked to rheumatoid arthritis.