FN1 and neoplasm: In the stroma of human carcinomas, cancer-associated fibroblasts (CAFs) are the most abundant cell types and play a significant role in tumor cell growth, angiogenesis, and invasiveness (Figure 1).42–46 CAFs are also responsible for the deposition of key extracellular matrix (ECM) proteins (e.g., collagen, fibronectin, and laminin) as well as secreting ECM-degrading enzymes (e.g., matrix metalloproteinases),42,43 which promotes migration of CAFs and degradation of the ECM, allowing the invasion of tumor cells.47