Fig. 2
From: Role of the S100 protein family in rheumatoid arthritis
S100A8/9 S100A12 binding of RAGE and TLR-4 receptor S100A8/9S100A12 protein can act as a cytokine to activate TLR or anger-mediated innate immune pathway, TLR, or anger mediated signaling pathway may lead to factors that increase inflammation, such as TNF-α, IL-1β, and IL-6 secretion of inflammatory cytokines, can in turn, stimulate itself, causing a vicious cycle of inflammation