Tumours contain a subpopulation of cells, called cancer stem cells (CSCs), which are self-renewing and tumorigenic and play a role in the resistance against chemotherapy and radiotherapy6–8; therefore, we aimed to determine the efficient methods of identifying therapeutic targets using a CSC model of ornithine decarboxylase (ODC)3–5 to characterize intracellular events based on the 5mC methylome and transcriptome data. Here, ODC1 is linked to cancer.