TLR7 and psoriasis: The initial clinical observation of a case of psoriasis exacerbated by topical treatment with the TLR7 agonist imiquimod [95], the occurrence of an evident IFN-α signature in psoriasis [96] and the presence in elevate number of pDCs in psoriatic skin [95,97] lead to further investigations about the role of pDCs in psoriasis.