This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Integrin is associated with all Except 
Select and explain. 
A. Rolling, B. Adhesion, C. Arrest, D. Transmigration
A: Rolling
Answer: A: Rolling 
Explanation: The rolling leukocytes are able to sense changes in the endothelium that initiate the next step in the reaction of leukocytes, which is firm adhesion to endothelial sur- faces. This adhesion is mediated by integrins expressed on leukocyte cell surfaces interacting with their ligands on endothelial cells (Fig. 2-5 and Table 2-2). Integrins are transmembrane heterodimeric glycoproteins that mediate the adhesion of leukocytes to endothelium and of various cells to the extracellular matrix. They are normally expressed on leukocyte plasma membranes in a low- affinity form and do not adhere to their specific ligands until the leukocytes are activated by chemokines. Integrins and Integrin Ligands ICAM-1 (immunoglobulin family) CD11/CD18 integrins (LFA-1, Mac-1) Firm adhesion, arrest, transmigration VCAM-1 (immunoglobulin family) VLA-4 integrin Adhesion Ref Robbins 9/e p35_36