It has been shown that aberrant gains at chromosome 20 are specifically associated with mutations in the tumour suppressor gene, TP53, by a survey of 50 cases of CRC, and they are also correlated with the progression of CRC, suggesting that the tumour suppressor pathway is involved in the maintenance of particular chromosomal regions (Wang et al, 2001; Leslie et al, 2003; Pledgie et al, 2005; Yde et al, 2007; Goodwin et al, 2008; Shor et al, 2008). This evidence concerns the gene TP53 and colorectal carcinoma.