DKK1 and cancer: For example, genes that encode DRs such as DCC, neogenin, UNC5B, UNC5C, or TrkC are repressed in multiple cancer types (Bernet et al, 2007; Luo et al, 2013; Forrest et al, 2016; Kong et al, 2016; Xing et al, 2021), while cancer cells can also escape DR‐mediated apoptosis through autocrine overexpression of ligands including DKK1 (Huang et al, 2014), Netrin‐1 (Kefeli et al, 2017), NT‐3 (Louie et al, 2013), Sema3E (Yong et al, 2016), or HGF (Baykal et al, 2003).