S100A9 and neoplasm: Taken together with the results above from S100A9−/−, TLR4−/− and RAGE−/− animals we conclude that a molecular interaction between S100A9 and TLR4 appears to be stimulatory for tumor cell growth in this experimental system, and that TGFβ expression may be a surrogate marker for S100A9/TLR4 interaction in vivo.