Final answer:
The cells referred to are tumor suppressor cells or similar regulatory cells which signal the cell to stop dividing or initiate apoptosis. They are not cancerous but are crucial in preventing cancer by ensuring controlled cell division and programmed cell death.
Step-by-step explanation:
The cells being described are likely tumor suppressor cells or other cells involved in the regulation of cell division and apoptosis. These cells do not become cancerous themselves, yet they require external signals to survive and function properly. When signaling is appropriate, these cells can either suppress or promote the cell division. For instance, tumor suppressor cells would normally help to prevent cancer by sending stop signals during the cell cycle, indicating problems with DNA or signaling the cell to undergo apoptosis if extensively damaged. Defects in these signaling pathways may lead to the avoidance of apoptosis and contribute to uncontrolled cell division, resulting in cancer. Therefore, although not cancerous themselves, these regulatory cells play critical roles in maintaining the balance of cell proliferation and death, and when this balance is disrupted, cancer can occur.