Interestingly, co-treatment of the cultures with combinations of the two agents increased these effects more than each agent by itself (Fig. 5:b). Densitometric analysis of typical western blot experiments show down regulation of NF-κB and MMP-13 in HCT116 cells treated with either 5-FU, curcumin or/and 5-FU (Fig. 5:a,b). Taken together, these data suggest that fibroblasts promote tumor cells progression in the co-culture microenvironment, at least in part through NF-κB pathways and this could be blocked by curcumin, thereby sensitizing CSCs to 5-FU treatment. This evidence concerns the gene MMP13 and neoplasm.