TNF and psoriasis: Research suggested that in early psoriasis, nucleic acids and various antimicrobial peptides released by damaged keratinocytes activated innate immune cells, including plasmacytoid DCs (pDCs) and macrophages, to produce tumor necrosis factor TNF-α, leading to the maturation of resident dermal DCs and the differentiation of monocytes into inflammatory DCs (iDCs) [57].