CRISPR-based targeted methylation of the MGMT promoter, using a chimeric fusion protein “d3A” consisting of a deactivated Cas9 (dCas9) with an epigenetic editor (DNA methyltransferase 3A catalytic domain), has been proven to downregulate MGMT expression and enhance susceptibility to temozolomide in several studies using glioblastoma cell lines [176,177]. Here, MGMT is linked to glioblastoma.