This occurs because keratinocytes are part of the immune system as well as the endothelial cells, playing a central role in the activation of pathways involved in psoriasis immunopathogenesis, acting firstly as an antigen presenting to T-lymphocytes.32, 33, 34 Herein, the same as in psoriasis, the intense staining of IL-17 in GT demonstrates that this interleukin is also involved in the pathogenesis of this oral lesion. The gene discussed is IL17A; the disease is psoriasis.