Chemoresistance of tumour cells can be provoked by mutations in oncogenes (eg, K-ras), loss of tumour suppressors (eg, p53, p16INK4) or dysregulation of genes involved in cell cycle cell proliferation, signal transduction, angiogenesis or apoptosis (Lee et al, 2005; Kleeff et al, 2006). This evidence concerns the gene CDKN2A and neoplasm.