In this study, we dissected RON signaling in human breast cancer cells and discovered, for the first time, that mTORC1 is the key downstream mediator of RON-driven metastasis: blocking the mTORC1 pathway using inhibitors, and/or novel RON mutants, prevent RON-dependent colony formation, migration, and metastasis. The gene discussed is MST1R; the disease is breast carcinoma.