Figure 1.

Important S100 signaling pathways. Most S100 proteins signal via the RAGE receptor, whereas a small selection also signals via TLR4. The pathways sum up the most important downstream signaling effects of S100A8 and S100A9, the most thoroughly studied S100 proteins. S100A8 can induce autophagy via RAGE, while S100A9 may induce cell differentiation via TLR4/Erk-signaling. Additionally, many S100 members can bind p53; the figure highlights the three proteins that are recognized inhibitors of the tumor suppressor.