RAD9A and cancer: Decreased RAD9A levels due to an RNA interference approach in prostate cancer cell lines dramatically reduce tumorigenicity in nude mouse xenografts, indicating not only that RAD9A has a critical, causal role in this type of cancer, but also suggesting that it plays a major role in DNA damage resistance and genomic integrity (Lieberman et al., 2017[45]; Zhu et al., 2005[80], 2008[79]).