More than 45 % of prostate tumors have aberrantly high levels of RAD9A as a result of intron 2 hypermethylation and hypermethylation of this site was also found in breast cancer (Broustas et al., 2012[10]; Cheng et al., 2005[12]; Lieberman et al., 2018[46]). Here, RAD9A is linked to breast cancer.