Protein levels of IL-37 in peripheral blood mononuclear cells (PMBCs) and dendritic cells were increased by cytokines associated with the pathogenesis of psoriasis, such as IL-1β, IL-18, IFN-γ, and TNF-α [67]; however, in human keratinocytes, only TNF-α among these cytokines increased mRNA levels, but not the protein levels, of IL-37 [85]. Here, IL37 is linked to psoriasis.