This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammation & Repair, Subject name: Pathology
Exogenous pyrogen is? 
Select and explain. 
A. TNF-a, B. Lipopolysaccharide, C. Neurotropic factor, D. IL-6
B: Lipopolysaccharide
Answer: B: Lipopolysaccharide 
Explanation: Ans. is 'b' i.e., Lipopolysaccharide * Pyrogens may be exogenous or endogenousa) Exogenous - Bacterial toxins (eg: LPS)b) Endogenous-IL-1, TNF-a, IL-6, Interferons, Ciliory's neurotropic factor