COL1A1 and ductal breast carcinoma in situ: Comparative gene expression profiling of myoepithelial cells of cancerous (DCIS) and normal breast tissue showed up regulation of several proteases (cathepsin F, K, and L, MMP2, and PRSS19), protease inhibitors (thrombospondin2, SERPING1, cytostatin C and TIMP3), and collagens like COL1A1, COL3A1, COL6A1 in DCIS tissue67,68.