The integration of integrative subtypes analysis, allowed for defining very important differences in the rates of recurrence among breast cancer subgroups allowing the identification of ER+/HER2- patients having a markedly increased risk of late disease relapse up to 20 years after diagnosis (representing about one-quarter of ER+ breast cancers) and the prediction of the risk of distant recurrence after five years in ER+/HER2- patients; this analysis allowed also the identification of a subgroup of TNBC patients with a better outcome, remaining largely relapse-free after 5 years [74]. The gene discussed is ESR1; the disease is breast cancer.