TP53 and neoplasm: Given the prominent role of IDH1 in LGG, we stratified LGG tumor samples by the IDH1 mutation status and further examined the effect of the other 31 MDGs within the IDH1 mutation stratum and the IDH1 wild-type stratum and found that TP53 mutations are now significantly associated with more hypo-methylation genome-wide in each stratum (Additional file 3: Text S1).