ERBB2 and breast carcinoma: For example, Duchnowska identified a 13 gene BrM predictionsignature for HER2+ breast cancer [28], and this was further refined toa 3 gene classifier that included RAD51 (RAD51 homolog), HDGF (hepatoma-derivedgrowth factor), and TPR (translocated promoter region) genes.Interestingly, multivariate analysis revealed that this 3 gene signature washighly predictive of early BrM in the discovery cohort, but it was notconfirmed in the validation cohort.