MMP9 and psoriasis: Cells were lyzed and mRNA levels of inflammatory mediators or pro-inflammatory cytokine genes including nuclear factor NF-kappa-B1 (NF-κB1), IL-6, IL-1β and IL-8 and pathogenic gene markers of psoriasis including keratin 16 (KRT16), Fos gene 1 (FOSL1) and matrix metalloproteinase 9 (MMP9) were determined by RT qPCR.