Definition
The process of controlling the production of a gene product. This can be turning a gene ‘on’, ‘off’ or regulating how much product is produced.
Use in clinical context
For a cell to carry out its function the right genes must be expressed at the right time and in the right quantity, then ‘turned off’ when no longer needed. This process is tightly controlled because expressing a gene at the wrong time in the wrong cell can have serious consequences. Gene expression can be altered in diseases such as cancer where genes that control when a cell stops dividing are turned off.