Similarly, mammary fibroblasts become progressively altered during malignant progression, showing increased expression of ECM remodeling proteins COL11A1, prolyl 4-hydroxylase A2 and cathepsin V, in DCIS-associated fibroblasts compared to normal tissue, and further increased expression in fibroblasts adjacent to IDC (Table 5) [82, 96–99], suggesting that these proteins contribute to a microenvironment favorable for breast cancer progression. The gene discussed is CTSV; the disease is ductal breast carcinoma in situ.