Increased deposition and re‐organization of collagens, fibronectin, and proteoglycans is observed in the transition from ductal carcinoma in situ, DCIS, to locally invasive disease and also in later stages and metastasis (Fu et al., 2014; Rybarczyk & Simpson‐Haidaris, 2000). This evidence concerns the gene FN1 and ductal breast carcinoma in situ.