Interestingly, high secretion of TGF‐β1 by the CRC cells, and thus stromal TGF‐β signaling, was essential at the initial phase of liver metastasis, since a 24 hour  induction of TGF‐β secretion directly after splenic injection was sufficient to increase liver colonization.59 The gene discussed is TGFB1; the disease is colorectal carcinoma.