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: Pathology
Fractalkine is also called  --------------. 
Select and explain. 
A. CXCL8, B. RANTES, C. MCP-1, D. CX3CL 1
D: CX3CL 1
Answer: D: CX3CL 1 
Explanation: CX3 C chemokines contain three amino acids between the first two cysteines. The only known member of this class is called fractalkine (CX3 CL1). This chemokine exists in two  forms:  a  cell  surface-bound protein induced on endothelial cells by inflammatory cytokines that promotes strong adhesion of monocytes and T cells, and a soluble form, derived by proteolysis of the membrane-bound protein, that has potent chemoattractant activity for the same cells.
Reference-Robbins BASIC PATHOLOGY 10th edition pg-172