HER2 intracellular domain(ICD), HER2 extracellular domain(ECD) and HER2 mRNA were assessed using AQUA. 
AQUA
For HER2 protein evaluation, CB11 was used to measure ICD and SP3 to measure ECD of the HER2 receptor.  HER2 mRNA was correlated with ICD HER2, as measured by CB11 HER2, with ECD HER2 as measured by SP3 (Pearson's Correlation Coefficient, r = 0.66 and 0.51 respectively) and with FISH HER2 (Spearman's Correlation Coefficient, r = 0.75). 
CB11
For HER2 protein evaluation, CB11 was used to measure ICD and SP3 to measure ECD of the HER2 receptor.  HER2 mRNA was correlated with ICD HER2, as measured by CB11 HER2, with ECD HER2 as measured by SP3 (Pearson's Correlation Coefficient, r = 0.66 and 0.51 respectively) and with FISH HER2 (Spearman's Correlation Coefficient, r = 0.75).  Multivariate analysis showed that in the presence of pre-specified set of prognostic factors, among all biomarkers only ECD HER2, as measured by SP3, is strong prognostic factor for both TTP (HR = 0.54, 95% CI: 0.31-0.93, p = 0.027) and OS (HR = 0.39, 95%CI: 0.22-0.70, p = 0.002).



SP3
In addition, HER2 mRNA status was assessed using RNAscope assay ERRB2 probe. 
RNAscope assay ERRB2 probe