USP4 and cancer: Major cancer pathways including p53, Wnt/β-catenin, TGF-β, and NF-κB signaling pathways are modulated by USP4, whereas regulation of TGF-β and NF-κB signaling pathways is also involved in other diseases, including spinal cord injury, liver fibrosis and cirrhosis, and pathological scarring (Xiao et al., 2012; Zhang et al., 2012; Yun et al., 2015; Cao et al., 2016; Hwang et al., 2016; Jiang et al., 2017; Qiu et al., 2018; Qin et al., 2019; Wu et al., 2019; Huang et al., 2020; Lai et al., 2020).