GP2 and breast cancer: Besides, the 5-year median follow-up data of a phase IIb study (NCT00524277) has indicated that 6 3/4-week-interval vaccinations of 500 μg of GP2 in 125 μg of GM-CSF improved rarely in 5 year DFS (77.1 vs. 77.6% as the placebo control, p = 0.9142) but dramatically in recurrence rate, which was down to 0% in breast cancer patients (HER2/neu immunohistochemistry 1–3 +) after adjuvant trastuzumab therapy (Patel et al. 2021b), and phase III trial was designed similarly (Patel et al. 2021a).