Physcion has been found to present a quantitative and temporal relationship in inhibiting the metastasis and proliferation of RA–fibroblast-like synoviocytes cultured in vitro.[15] At the cellular level, kaempferol exerts anti-inflammatory effects, reducing the production and mRNA expression of pro-inflammatory cytokines, such as thymic stromal lymphopoietin, TNF-α, and interleukin-18.[16]. Here, IL18 is linked to rheumatoid arthritis.