The high proportion of RASSF1A promoter methylation in tumours agrees with earlier reports in the literature, which have found RASSF1A to be hypermethylated in 52–94% of tumour DNA samples (Astuti et al, 2001; Harada et al, 2002; Wong et al, 2004; Yang et al, 2004, 2007; Banelli et al, 2005; Lazcoz et al, 2006; Michalowski et al, 2008). This evidence concerns the gene RASSF1 and neoplasm.