Furthermore, ROS can also influence cellular signal transduction pathways, also known to play an important role in the pathogenesis of psoriasis, such as mitogen-activated protein kinase/activator protein 1 (MAPK/AP1), nuclear factor κB (NF-κB) and Janus kinase-signal transducers and activators of transcription (JAK/STAT) [87,116,117,118,119]. The gene discussed is MAPK1; the disease is psoriasis.