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: Pharmacology
Which of the following represents the mechanism of action of Eternacept? 
Select and explain. 
A. Blocking tumor necrosis factor, B. Blocking bradykinin synthesis, C. Blocking cyclo-oxygenase-2, D. Blocking lipoxygenase
A: Blocking tumor necrosis factor
Answer: A: Blocking tumor necrosis factor 
Explanation: Etanercept is a fusion protein of TNFRII and the Fc region of IgG1, that binds to TNF and prevent the molecule from interacting with its two receptors, TNFRI and TNFRII, thereby stopping signaling events. TNF is involved in inflammatory and immune responses. Etanercept can also modulate biologic responses regulated by TNF. Ref: Handbook of Dermatologic Drug Therapy By Steven R. Feldma, Page 76