If a cell loses control of gene expression, what happens?

Healthy, mature cells develop.

The cell can carefully use its resources.

Abnormal, unhealthy cells develop.

The cell becomes more specialized.

Abnormal, unhealthy cells develop

Explanation:

Gene expression is the process through which genes are turned on through transcription, and to some extent through the translation of the mRNA.

Gene expression is highly regulated to ensure the cell can create the correct combination of proteins to carry out it's tasks. If gene expression is out of control, the mRNAs that are transcribed in the cell are not properly regulated, and therefore the proteins in the cell are not regulated. Since proteins carry out essentially every function in the cell, the cell becomes unhealthy, and incorrectly uses its resources.

Accurate control of gene expression also ensures that the cell can perform specialized functions, it is what makes a heart cell distinct from a brain cell, for example. Therefore, if it is out of control, cells will not be specialized correctly.