The subject matter described herein is directed to methods of modifying the micro-environment of a target cell or The methods comprise systemically administering to a subject a composition comprising a vector, wherein the vector comprises a construct for the expression of a trap in the target cell, wherein the trap is expressed in the target cell thereby modifiying the micro-environment. Also described herein are methods of reducing metastasis of a cancer comprising, systemically administering to a subject suffering from the cancer, a composition comprising a vector, wherein the vector comprises a construct for the expression of a trap, wherein the trap is delivered to and then expressed in tissue susceptible to metastasis, wherein metastasis of the cancer to the tissue is reduced. Compositions for carrying out the methods are also described.
