This overexpression with respect to normal tissue correlates with tumor grade where high RhoB expression was found in grade III ductal breast cancers as compared to grade I. Consistent with these findings, Médale-Giamarchi et al. showed a positive crosstalk between RhoB expression and ER-α expression and the significant role of RhoB in regulating the proliferation of ER-α positive breast cancer cells [60]. This evidence concerns the gene RHOB and breast cancer.