Since psoriasis is thought to occur as a result of deregulated T-cell function [32, 33], it is interesting that both PPARγ [34–36] and PGE2 [37–39] act as T-cell and dendritic cell immunosuppressants and that topical application of PGE2 has been shown to result in clinical improvement of psoriatic lesions [40]. The gene discussed is PPARG; the disease is psoriasis.