The cluster of differentiation ( cluster of designation) (often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophenotyping of cells. In terms of physiology, CD molecules can act in numerous ways, often acting as receptors or ligands (the molecule that activates a receptor) important to the cell.
.@joannbc We use to name them after CD proteins/molecules in Immunology http://t.co/tWaX6zlfaV i.e.: cd11, cd117, cd45 :) @princesslaurie