Figure 3A demonstrates that NF-κB activity could be induced by transient exposure of colorectal cancer cell lines to 5-FU. In combination with 5-FU, disulfiram, an NF-κB inhibitor, strongly enhances the cytotoxicity of 5-FU and totally reverses 5-FU resistance in two 5-FU-resistant colorectal cancer cell lines in vitro (Wang et al, 2002). Thus, targeting NF-κB may be a new measure to overcome TS inhibitor resistance. This evidence concerns the gene NFKB1 and colorectal cancer.