Methods of inhibiting metastasis in cancer patients are provided, wherein the methods comprise reducing TGFβ signaling, for example, by reducing TGFβ receptor II expression in myeloid cells. Vectors comprising a TGFβ receptor II RNAi nucleic acid sequence operably linked to a myeloid specific promoter also are provided. A method of diagnosing cancer in an individual by determining TGFβ receptor II expression in myeloid cells in the individual is provided. Additionally, a method of modulating TGFβ activity in myeloid cells in a cancer patient comprising administering a regulator of at least one of the GSK3 and PI3K pathways to the patient is provided.
