STAT3 and psoriasis: Numerous studies have demonstrated that inflammation related pathways, such as nuclear factor-kappa B (NF-κB) pathways, signal transducer and activator of transcription 3 (STAT3) pathways and mitogen-activated protein kinase (MAPKs) pathways were involved in psoriasis (Haase et al., 2001; Sun et al., 2017; Nguyen et al., 2018; Wang et al., 2019; Xu et al., 2019).