In addition to the intra-tumor cellular heterogeneity, the cancer cells co-exist with different non-cancerous cells like the Cancer associated fibroblasts (CAFs), endothelial cells, and immune cells (like macrophages, microglia, and lymphocytes); and the non-cellular components like extracellular matrix components (ECM) (fibronectin, laminin, collagen, hyaluronan, integrin etc.)to form a complex three dimensional (9) ecosystem called tumor microenvironment(TME) (5, 10). This evidence concerns the gene FN1 and cancer.