These findings point out that targeting CD6 and its ligand CD318 could both suppress autoimmune diseases through its effects on differentiation of effector CD4 cell subsets, while also activating the anti-cancer cytotoxic properties of CD8+ and NK cells, creating the potential for an approach to cancer immunotherapy that would suppress rather than instigate serious autoimmune diseases (Figure 1). Here, CD4 is linked to autoimmune disease.