The case study consisted of patients with resected HER-2 positive breast cancer who were enrolled in the adjuvant N9831 trial (NCT00005970), which was a Phase III trial where patients were randomized to three arms: (Arm A) doxorubicin and cyclophosphamide followed by weekly paclitaxel, (Arm B) same as Arm A but followed by 1 year of sequential trastuzumab, or (Arm C) same as Arm A but with 1 year concurrent trastuzumab started the same day as weekly paclitaxel [19]. The gene discussed is ERBB2; the disease is breast cancer.