NEDD4 and neoplasm: NEDD4-1 exerts the dichotomous roles as an oncoprotein (Eide et al. 2013; Amodio et al. 2010; Wang et al. 2007; Xu et al. 2015; Huang et al. 2017; Li et al. 2015; Sun et al. 2017; Kim et al. 2008a; Jung et al. 2013; Singh et al. 2011; Verma et al. 2017; Yim et al. 2009) and a tumor suppressor (Zhou et al. 2014; Trotman et al. 2007; Liu et al. 2013; Huang et al. 2015; Huang et al. 2020a; Zeng et al. 2014; Platta et al. 2012) in cancer cells (Fig. 2A).