What is a hallmark of malignant cells compared to normal cells?

Malignant cells are characterized by their ability to divide rapidly and uncontrollably. This rapid proliferation is a key hallmark of cancer and distinguishes malignant cells from normal cells, which exhibit regulated growth and division.

In normal tissues, cell division is tightly controlled and occurs only when necessary for growth, repair, or replacement of cells. In contrast, malignant cells bypass these regulatory mechanisms, leading to an increase in cell division that is not only rapid but also can lead to the formation of tumors and the spread of cancerous cells to other parts of the body through processes such as metastasis.

The other options highlight characteristics of normal cells: limited cell division reflects the control that normal cells have; tight adherence to each other indicates the normal cellular structure and organization; and orderly growth refers to the way normal cells regulate their proliferation in a planned manner. Therefore, the distinction of rapidly dividing is what firmly identifies malignant cells as opposed to their normal counterparts.