Turning ‘on and off’ of the genes refers to the cell’s ability to express (turn ON) or repress (turn OFF) the genes at a certain time. Each cell expresses only a fraction of its genes at any given time. The rest of the genes remain repressed. This process is known as gene regulation.
What happens if gene regulation fails?
If gene regulation fails, protein production can go out of control and lead to abnormal multiplication of cells, which is characteristic of diseases such as cancer. For a cell to become cancerous, many genetic changes have to take place. Some people are born with one such mutation, while some mutations develop over a lifetime.