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What is Epigenetics

What makes the cell types in our bodies remember their identity? What prevents them from becoming cancer cells? Why do we inherit some traits from our father, others from our mother? How do our experiences and environment influence us? These questions are addressed by a scientific field called epigenetics, which studies heritable changes in the absence of alterations in our DNA.


Literally translated, epigenetics means around genetics. Epigenetics is the study of cellular and physiological traits that could be inherited but are not caused by actual changes to our DNA, or genetic code.

Epigenetics refers to natural control mechanisms that influence gene expression. Their role is often compared to computer software. Think of DNA, and the genes we are born with, as the human hard drive. Everything a cell does is controlled by this hard drive. But, a hard drive cannot work without software. Epigenetics is the software package. Researchers believe that every cancer may have 50 to several hundred genes that have working “hard drives,” but their epigenetic “software” is causing them to act in a way that can lead to cancer development.

In the world of cancer, epigenetics is considered an emerging field, but its study is not new.  Johns Hopkins investigators Andrew Feinberg and Bert Vogelstein first reported epigenetic changes in human cancer in 1983. Renowned veteran cancer scientists like Donald Coffey, Stephen Baylin, Peter Jones, Jim Herman, William Nelson, and Dr. Feinberg have been studying this biological process for decades, but it did not gain widespread acceptance until the early 2000s.

Dr. Nelson, Kimmel Cancer Center Director, recalls in the 1990s when it was difficult to get a scientific paper on the topic published. Technologies that allowed science to analyze DNA at the molecular level and the tenacity of a relatively small group of scientists proved its validity.

The long concealed mysteries of what some have referred to as the “ghost in our genes,” referring to epigenetic mechanisms’ ability to alter gene expression without leaving a permanent mark on DNA, are beginning to be uncovered. Now, what was once an outcast in cancer research is being heralded as one of the most promising fields of study in cancer medicine.

With a group of epigenetic scientists, who Dr. Nelson characterizes as “second to none,” the Johns Hopkins Kimmel Cancer Center in Baltimore has become a hub for epigenetic discovery and clinical translation. 

Learn more about epigenetics from Dr. Feinberg, professor of medicine and director of the Center for Epigenetics at the Johns Hopkins Institute for Basic Biomedical Sciences.