Final answer:
A cytokine with multiple functions exhibits the property of pleiotropy, enabling it to carry out various roles in immune response regulation and cell signaling.
Step-by-step explanation:
When a cytokine has multiple functions, this property is known as pleiotropy. Cytokines are vital chemical messengers in the immune system that can regulate cell differentiation, proliferation, gene expression, and cell trafficking to effectuate various immune responses.
They often act locally as autocrine or paracrine factors, meaning they affect the cells that secrete them or nearby cells, respectively. An example includes interferons, which can inhibit viral replication, prompt neighboring cells to destroy RNA and reduce protein synthesis, as well as activate other immune cells for functions such as tumor surveillance.