Which statement best describes cancer cells' behavior, including ongoing growth and potential spread?

• A. Differentiated cells
• B. Apoptotic cells
• C. Cancer cells
• D. Stem cells

Answer: (C)

Uncontrolled, ongoing growth and the ability to spread distinguish cancer cells from normal cells. Cancer cells harbor mutations that disrupt normal cell-cycle control and cell death signals, so they keep dividing instead of stopping or dying when they should. They also often gain the ability to invade nearby tissues and travel to distant sites, a process called metastasis. Differentiated cells are specialized and usually do not divide much; apoptotic cells are those undergoing programmed cell death; stem cells can divide but under regulated signals. So describing cancer cells as continuously growing and potentially spreading best captures their defining behavior.