In vitro and in vivo methods for identifying compounds capable of targeting suppressed cancer cells such as micrometastatic cells. The in vitro method includes the steps of comparing the response to a test compound of cancer cells grown on a suppressing cell support matrix which causes suppression of a malignant phenotype in a growing cancer cell and on a non-suppressing cell support matrix. The in vivo method includes a step of co-injecting labeled cancer cells with a malignant-phenotype suppressing matrix into a test animal to produce suppressed micrometastatic cells therein.
