In addition, a presentation29 in 2018 from a combined analysis of the N9831 and NSABP B31 studies showed that the risk of recurrence after 5 years was higher in patients with oestrogen receptor-positive and HER2-positive breast cancer than those with oestrogen receptor-negative and HER2-positive disease; this finding is relevant for PERSEPHONE because of the inclusion of a high proportion of oestrogen receptor-positive patients. The gene discussed is ERBB2; the disease is breast cancer.