CD4 and alopecia universalis congenita: Autoimmune uveitis (AU), a sight-threatening disease affecting ocular tissues such as the ciliary body, vitreous body, choroid and retina, is initiated by the aberrant activation of CD4+ T cells and subsequent recruitment of inflammatory cells (granulocytes, monocytes/macrophages) to the eyes, which ultimately causes tissue impairment and potentially leads to blindness (71, 72).