β5i is widely expressed in the human thymus. (A) β5i-expressing cells are distributed in both cortex and medulla and are not stained with Ab for keratin. The lower panel shows a magnified image of the cortical area. (B) Cells expressing β5i at high levels in the cortex are stained with Ab for CD11c. Thus, cortical DCs express β5i at high levels. Bar represents 50 μM.