Most research efforts have been focused on the underlying molecular mechanisms of CRC carcinogenesis, and a variety of candidate genetic markers with predictive value of outcome have been discovered by studying the cancerous tissues (e.g., KRAS expression, levels of DNA mismatch repair, 18q deletion, and p53 expression).7–9,18,19 However, personal genetic background might contribute greatly to this disease. This evidence concerns the gene KRAS and colorectal carcinoma.