Decades ago, psoriasis was thought to be driven by the keratinocytes in the epidermis. The discovery that immune cells mediated the disease explained the efficacy of immunosuppressive therapies ...

Furthermore, studies have identified high levels of iron in the skin of psoriasis patients. The epidermis of psoriasis patients is also known to produce high levels of hepcidin, which is thought ...

investigated whether IL-21 can induce keratinocyte proliferation and epidermal hyperplasia as seen in psoriasis ... and infiltration of the dermis and epidermis with inflammatory cells.