PPARD and psoriasis: In contrast to these anti‐inflammatory actions, PPARβ/δ increased expression in murine epidermis provoked a psoriasis‐like phenotype, and its expression is elevated in human psoriatic lesions (Appendix Fig S2F), where it was proposed to contribute to the persistence of activated T cells (al Yacoub et al, 2008; Romanowska et al, 2010).