Molecular-targeted therapy is the best example of accurate, causal therapy since the disease-causing molecular defect is a target of a drug. It is one of the cornerstones of personalized medicine. A therapeutic drug is often a small molecule drug that targets markers inside the cell or an antibody that attaches to specific targets on the outer surface of cells. Most molecular-targeted therapies are used in the treatment of cancer. They have contributed to the fact that several cancers are becoming a chronic disease (Pavlovic et al., 2017).

The most common mechanisms of epigenetic silencing (aberrant DNA methylation and modification of histones) have been used as targets for molecular therapeutics that are clinically applicable in the cancer treatment. These drugs could replace cytotoxic chemotherapy in near future