SmgGDS promotes cell proliferation, migration, and NF-kB activity in breast, lung, prostate, and pancreatic cancer lines (Tew et al., 2008; Zhi et al., 2009; Berg et al., 2010; Schuld N. J. et al., 2014; Hauser et al., 2014; Gonyo et al., 2017; Brandt et al., 2020) and promotes tumorigenesis of human breast cancer and lung cancer xenografts in mouse models (Schuld N. et al., 2014; Hauser et al., 2014). This evidence concerns the gene RAP1GDS1 and breast cancer.