EREG and cancer: In inverse co-culture at both time points and standard co-culture at 72 h 26 genes were mutually expressed, among them genes of the KEGG pathway Proteoglycans in cancer, like Fibronectin 1 (FN1), Hepatocyte Growth Factor (HGF), Epiregulin (EREG) and Tissue Inhibitor of Metalloproteinases 1 (TIMP1) (Fig. 8c, Table 2).