This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Interferon is....in nature - 
Select and explain. 
A. Protein, B. Lipid, C. Polysaccharides, D. All of the above
A: Protein
Answer: A: Protein 
Explanation: All cytokines are protein mediators so interferon Reff: Anantharayan & Panikers textbook f microbiology 9th edition pg:153