If a cell loses control of gene expression, abnormal and unhealthy cells develop.
Explanation: The gene expression is highly regulated. The process of transcription affects gene expression. At every level, it is required to check whether the correct gene and protein are made or not. If gene expression is switched off, the central dogma gets disturbed eventually cell machinery will not be able to have a check on the transcription and translation processes eventually abnormal, cancerous and unhealthy cells will develop.