This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Not a cell adhesion molecule 
Select and explain. 
A. Integrin, B. Selectin, C. Cadherin, D. Spectrin
D: Spectrin
Answer: D: Spectrin 
Explanation: Spectrin is a peripheral proteinAdhesive glycoproteins and adhesion receptors are structurally diverse molecules variously involved in cell-to-cell adhesion, linking cells to the ECM, and the interactions between ECM components. Prototypical adhesive glycoproteins include fibronectin (a major component of the interstitial ECM) and laminin (a major constituent of basement membrane). Integrins are representative of the adhesion receptors, also known as cell adhesion molecules(CAMs); the CAMs also include immunoglobulins, cadherins, and selectins.Ref: Robbin&;s; 9th edition; Chapter 1; The Cell as a Unit of Health and Disease