On the basis of the extensive evidence of the implication of MKP-1 in resistance to anti-cancer agents, as well as on the preliminary pre-clinical evidence by our group and others of the implication of MKP-1 in anti-EGFR therapy resistance (Takeuchi et al, 2009), we hypothesised that MKP-1 expression in human CRC tumours may be a marker of resistance to anti-EGFR moAb. This evidence concerns the gene EGFR and colorectal carcinoma.