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
All the following receptors belong to the steroid receptor superfamily, EXCEPT: 
Select and explain. 
A. Thyroid receptor, B. Retinoid receptor, C. Vitamin D3 receptor, D. Epinephrine receptor
D: Epinephrine receptor
Answer: D: Epinephrine receptor 
Explanation: Adrenergic receptors (epinephrine and norepinephrine) are membrane bound G-protein coupled receptors and does not belong to steroid receptors. Adrenaline binds to cell membrane receptors alter intracellular cAMP concentration, alter protein kinase A and regulate cell function. Ref: Essentials of Medical Pharmacology By K D Tripathi, 5th Edition, Pages 213-4 ; Vitamins and Hormones By Gerald Litwack, Volume 55, Page 131