In psoriasis, production of LL-37 and hBD-2 is increased, whereas LL-37 is able to form complexes with self-RNA resulting in the activation of TLR7 in plasmacytoid dendritic cells (pDCs) and TLR8 in myeloid DCs and to enable pDCs to recognize self-DNA through TLR9 and therefore contributes to psoriasis pathogenesis by IFN-γ-induced activation of myeloid dendritic cells (mDCs) and keratinocytes and Th1/Th17 differentiation (Bangert et al., 2011; Takahashi and Gallo, 2017). This evidence concerns the gene TLR9 and psoriasis.