JUNB and psoriasis: Whereas deletion of Junb together with Jund in mouse keratinocytes resulted in a skin phenotype resembling psoriasis (Zenz et al., 2005), JUNB is upregulated in psoriatic skin (Haider et al., 2006) and a recent comprehensive meta-analysis of the psoriasis transcriptome has revealed an enrichment of AP-1-binding sites among psoriasis-increased genes and pinpointed the increased expression of JUNB in psoriasis skin to keratinocytes (Swindell et al., 2013), suggesting a role for the AP-1 pathway and JunB as a critical checkpoint of epidermal homeostasis.