IFN-α produced from the activated plasmacytoid DCs plays a crucial role in the early phase of psoriasis, further activating dermal DCs and triggering downstream T cell-mediated adaptive immunity [6], whereas in a imiquimod-induced psoriasis-like skin inflammation model, the signaling via TLR7 was intermittently activated and could directly induce IL-23, TNF-α, and IL-6 expression from DCs [35]. Here, TLR7 is linked to dermatitis.