DNA methyltransferase inhibitors are compounds that block the activity of enzymes responsible for adding methyl groups to DNA. This process, known as DNA methylation, can regulate gene expression and is often altered in various diseases, including cancer. By inhibiting these enzymes, these drugs can reactivate silenced genes, potentially leading to therapeutic benefits. These inhibitors are being studied for their role in cancer treatment, as they may enhance the effectiveness of other therapies. Some examples of DNA methyltransferase inhibitors include azacitidine and decitabine, which are used in specific types of blood cancers to improve patient outcomes.