Aberrant methylation of the HPP1 and RUNX3 genes has been demonstrated in gastrointestinal and other human tumours (Liang et al, 2000; Young et al, 2001; Guo et al, 2002; Li et al, 2002; Sato et al, 2002; Shibata et al, 2002; Kato et al, 2003; Xiao and Liu, 2004). The gene discussed is RUNX3; the disease is neoplasm.