This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Which of the following inflammatory mediator doesn't cause fever: 
Select and explain. 
A. Nitric oxide, B. Prostaglandin, C. IL-1, D. TNF-alpha
A: Nitric oxide
Answer: A: Nitric oxide 
Explanation: Pyrogens A pyrogen is a substance that induces fever. These can be either internal (endogenous) or external (exogenous) to the body. The bacterial substance lipopolysaccharide (LPS), present in the cell wall of some bacteria, is an example of an exogenous pyrogen. Endogenous Pyrogens IL 1 TNF PGs Depyrogenation may be achieved through filtration, distillation, chromatography, or inactivation.