Similar results were identified when the cohorts were stratified according to HER2 targeted therapy or ER status; the response rate in Group 2 was not different to Group 1 tumours (p = 0.575 and p = 0.375 in the ER negative and ER positive cases, respectively) or combined Group 1 and Group 3 tumours (p = 0.73 and p = 0.44 in the ER negative and ER positive cases, respectively). Here, ERBB2 is linked to neoplasm.