CD4 and oral lichen planus: It is believed that immune dysregulation plays a crucial role in the development of OLP and the primary lymphocytes implicated are believed to be CD8+ cytotoxic and CD4+ Th1 polarized T cells, which are driven by the identification of nonself antigens, activating T cell subsets that are directed towards oral keratinocytes and causing apoptosis of keratinocytes [9].