Figure 2.

CD9 regulates myeloid lineages. CD9 is expressed on the plasma membrane of different myeloid lineages and is associated with MHC-II and integrins on eosinophils and with FcRs on basophils, platelets, mast cells and macrophages. CD9 activates cells degranulation and cytokines secretion and is involved in cytokine-mediated chemotactic responses. Finally, CD9 regulates inflammation, allowing eosinophils to stimulate CD4⁺ T-cell activation and induce macrophage activation.