CD6 is a membrane glycoprotein expressed primarily in mature, activated T cells. Ligand binding of CD6, increases events such as adhesion, activation, proliferation, differentiation and survival [3–6]. In addition, CD6 mediates interaction between T cells and antigen-presenting cells, contributing to the maturation of immune synapses [6]. CD6-mediated costimulation contributes to the maturation of a Th1 pattern in human T cells and preferentially promotes a pro-inflammatory response characterized by the secretion of TNF-α, IL-6 and IFN γ [7].