Several observations support the importance of immune cells in the pathogenesis of psoriasis. Dendritic cells (DCs) are a key population of the immune system, bridging the breaks between innate and adaptive immunity. In psoriasis, certain DC populations like plasmacytoid DCs (pDCs) dominate the inflammatory skin. This study showed that during initial inflammation, an increased number of pDCs is activated, which results in the release of type I interferon (IFN-α). This Recommendation is of an article referenced in an F1000 Faculty Review also written by Franziska C. Eberle, Jürgen Brück, Julia Holstein, Kiyoshi Hirahara, and Kamran Ghoreschi.