Within the âseed and soilâ theory of organ tropic cancer metastasis is a growing compilation of evidence that S100A8/A9 functions as a soil signal that attracts cancer cells to certain organs, which prove beneficial to their growth. S100A8/A9âsensing receptors including Tollâlike receptor 4 (TLR4), advanced glycation end products (RAGE), and also important receptors we recently succeeded in identifying (EMMPRIN, NPTNβ, MCAM, and ALCAM) have the potential to become promising therapeutic targets. In our study, we prepared extracellular regions of these novel molecules and fused them to human IgG2âFc to extend halfâlife expectancy, and we evaluated the antiâmetastatic effects of the purified decoy proteins on metastatic cancer cells. The purified proteins markedly suppressed S100A8/A9âmediated lung tropic cancer metastasis. We hence expect that our novel biologics may become a prominent medicine to prevent cancer metastasis in clinical settings through cutting the linkage between âseed and soilâ.