Recent advances in molecular genetics have importantly improved our understanding of the development of colorectal cancer. The present review gives an overview of the clinical value of the tumour-suppressor gene, p53, and the CD44 cell adhesion molecule in colorectal cancer and the pitfalls encountered in the immunohistochemical detection of these proteins. Immunohistochemistry potentially forms a procedure applicable for routine diagnosis and prognostication. Therefore, p53 expression and the independent prognostic importance of CD44v6 expression is given particular emphasis, and other molecular events underlying colorectal carcinogenesis are only mentioned briefly.