A few families have been described in which Lynch syndrome patients display hypermethylation of the MLH1 promoter in tumour as well as in non-tumour tissue (Gazzoli et al, 2002; Miyakura et al, 2004; Suter et al, 2004; Hitchins et al, 2005; Valle et al, 2007a). This evidence concerns the gene MLH1 and Lynch syndrome.