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: Biochemistry
Regan enzyme is an isoenzyme of ? 
Select and explain. 
A. LDH, B. Creatinine kinase, C. Acid phosphatase, D. Alkaline phosphatase
D: Alkaline phosphatase
Answer: D: Alkaline phosphatase 
Explanation: Ans. is 'd' i.e., Alkaline phosphataseRegan enzyme (isoenzyme) is the isoenzyme of alkaline phosphatase.It arises from placenta know as carcinoplacental enzyme.It is elevated in about 15% fo cases of carcinoma of lung, liver and gut.