Indeed, when we examined cancer-associated fibroblasts (CAFs) by quantitative RT-PCR, and real-time PCR, we found a more than 20-fold overexpression of OSF-2 (relative expression ratio R = 21.18) in CAFs compared to tumor cells, supporting our hypothesis that OSF-2 expression/secretion appears to generate a tumor-friendly microenvironment (Figure 4B,C). This evidence concerns the gene POSTN and cancer.