These include growth factors such as vascular endothelial growth factor and platelet-derived endothelial cell growth factor (Fujimoto et al, 1998), microsatellite instability (Nakata et al, 2002), tumour suppression gene expression such as SMAD4 (Biankin et al, 2002) and the expression of mutated genes controlling response to DNA damage, such as GADD45a and p53 (Yamasawa et al, 2002). Here, SMAD4 is linked to neoplasm.