In addition to the acquisition of specific genetic alterations in the cancer cell, invasion is casued through exposure of epithelial cancer cells to paracrine signals that they receive from the tumor-associated stroma. Recent reports from our laboratory propesed that myofibroblasts are recruited in large numbers to the stroma of developing tumors. We are determined to characterize the role of stromal myofibroblasts in the supply of contextuale signals to promote cancer invasion.