A study found a gene expression signature that distinguished primary and metastatic adenocarcinomas and predicts the metastatic probability of these tumors; and a considerable proportion of the gene-expression signature described was composed of tumor COL gene expression, such as COL1A1 and COL1A2, both drivers of CAFs to synthesize collagen I fibers deposition resulting in stroma-associated fibrosis (34). The gene discussed is COL1A1; the disease is neoplasm.