This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cell Membrane and transpo protiens, Subject name: Physiology
Which cell adhesion molecules (CAM) is calcium mediated? 
Select and explain. 
A. Cadherin, B. NCAM, C. IgSF, D. Fibronectin binding protein
A: Cadherin
Answer: A: Cadherin 
Explanation: Type of CAM Subtypes Distribution Calcium- dependent 1. Cadherins 2. Selectins 3. Integrins - Most cells including epithelia - Migrating cells E.g.: leucocytes - b/w cells & intercellular substance. About 20 types; each attaching to an extracellular molecule. CALCIUM INDEPENDENT: 1. Neural cell adhesion molecule (NCAM) - nerve cells 2. Intercellular adhesion molecule (ICAM) - leucocytes.