Univariate analyses in the training dataset revealed that next to development of visceral organ metastasis (ever, as first site of metastasis and as the only metastasis) the 14-gene expression signature was also found to be significantly correlated to the histologic subtype of the tumour, ER status, PR status and molecular subtype of the primary tumour (p 0.003, p < .001, p < .001, p < .001 and p < .001, respectively). The gene discussed is ESR1; the disease is neoplasm.