The decreased decorin expression in prematurely senescent human breast stromal fibroblasts induced by ionizing radiation (a typical treatment for breast cancer) shown here fulfills the already tumor-promoting phenotype of these cells, which have been shown to display increased MMP activity and syndecan-1 up-regulation (also considered a poor prognostic factor for breast cancer progression) [19]. The gene discussed is SDC1; the disease is neoplasm.