As presented in Figure 6, among the WHO grade IV gliomas, the majority of the samples (63.33%) had methylated ABCB1, while in the WHO grade III it was less than half of the samples (46.66%); in the WHO grade II gliomas, none of the samples were found to be methylated in the ABCB1 promoter region. Here, ABCB1 is linked to glioma.