CCR4 and medullary thyroid gland carcinoma: Other genes exhibited lineage-specific expression patterns, including integrins (e.g., ITGAL/CD11a, ITGA4/VLA4), which were expressed more highly in CD8+ MTC; whereas the chemokine receptors CCR4 and CCR6, which have been implicated in homing to specific peripheral tissues such as the skin17,18, were more expressed in CD4+ MTC (Fig. 1e).