Interestingly, we found that communication between fibrocytes and cancer cells altered not only the cancer cell phenotype but also the fibrocyte phenotype toward a more mature connective tissue phenotype with further increased mRNA expression of collagen 1A1 (COL1A1) and 3A1 (COL3A1) and fibronectin (FN1) (Fig. 6D and Figs. S6C–S6F). This evidence concerns the gene COL1A1 and cancer.