Fig. 2

a Multiple comparison of gDNA hypomethylation median levels according rs1801133 variants (p = 0.033, d = 0.570) show that rGBM patients harboring the TT genotype variant presented with a significant and marked reduction on gDNA hypomethylation (median = 13.35%) with a 2.4-fold decrease when compared to CC (median = 33.34%, d = 1.189) and CT (median = 32.10%, d = 0.597) genotypes. We further observed a significant, moderate and negative correlation between TT or CC (rho = − 0.520; p = 0.003, figure 2b) genotypes and a non-significant, weak and negative correlation between TT or CT (rho = − 0.289; p = 0.06, figure 2c) variants and global gDNA hypomethylation levels