IRF9 and psoriasis: Given that ISGF3 has affinity for ISRE-like elements [67], [69], we favor a model in which STAT1-57 gene expression is activated by the ISGF3 complex in psoriasis lesions (Figure 8), particularly since both STAT1 and IRF9 were included among the STAT1-57 genes, and because we and others have demonstrated elevation of pSTAT1(ser727) and IRF9 protein in psoriatic epidermis (Figure 7) [70], [71].