TP53 and lymphoma: Moreover, reduced MS activity due to MS c.2756A>G results in lower rates of synthesis of methionine and SAM, which might be protective against SAM-dependent DNA hypermethylation that is an additional risk factor for cancer development (Figure 1; Matsuo et al, 2001; Mudd et al, 2001): several studies have demonstrated an association of DNA hypermethylation of tumour-suppressor genes such as p53, p15 and p16 with lymphomas (Baur et al, 1999; Moller et al, 1999; Gonzalez et al, 2000).