In the Netherlands, endocrine therapy is only recommended in hormone receptor-positive patients with lymph node positive disease or otherwise unfavourable tumour characteristics (high grade or size ≥ 2 cm)22, whereas in all the other countries adjuvant endocrine therapy is prescribed in all patients with hormone receptor-positive BC (for an overview of guidelines we refer to Supplementary Table S8). Here, NR4A1 is linked to neoplasm.