IRF9 and dry eye syndrome: Combined with the fact that both STAT1 and IRF9 were members of the STAT1-57 gene module, implying their co-expression in KCs/epidermis, these observations support a mechanism by which STAT1 and IRF9 (i.e., ISGF3) cooperatively bind an ISRE-like motif (GRAANNGAAAST) to drive expression of a cytokine hub transcription circuit within the psoriatic epidermis.