To address the possibility that MMP3 is a new target for blocking cancer-fibroblast interplay, the MMP-3 inhibitor was administered into co-culture media at concentrations (< 100 nM for mouse cell-lines, < 80 nM for human cell-lines) that do not affect the growth of fibroblasts and cancer cells for 6 days (Supplementary Figure 7). The gene discussed is MMP3; the disease is cancer.