Abstract Background There are multiple copies of mitochondrial DNA (mtDNA) present in each cell type. and they are strictly regulated in a cell-specific manner by a group of nuclear-encoded mtDNA-specific replication factors. This strict regulation of mtDNA copy number is mediated by cell-specific DNA methylation of these replication factors. Glioblastoma multiforme. https://spencertifieders.shop/product-category/cases/