clusters of differentiation (cd) molecules are important because they
Cluster of differentiation While CD molecules are very useful in defining leukocytes, they are not merely markers on the cell surface. While only a fraction of known CD molecules have been thoroughly characterised, most of them have an important function. In the example of CD4 & CD8, these molecules are critical in antigen recognition. Others (e.g., CD135) act as cell surface receptors for growth factors.