The more severe form of OLP in DM patients might be due to the altered immunological spectrum and the immune dysregulation caused by DM that is the base of the OLP pathogenesis, where several routes may trigger the induction of keratinocyte apoptosis by CD8+ T-cells in OLP, one of those is the increased secretion of TNF-α and IL-6. The gene discussed is CD8A; the disease is diabetes mellitus.