To evaluate the long-term maintenance of the molecular setting (i.e. ER−/PR−/HER2+) of the primary tumor, the immunoenzymatic and immunofluorescent analyses were repeated on a cellular spot obtained from DHSF-BR16 cells kept in culture for about 2 years, confirming the ER−/PR−/HER2+ phenotype in DHSF-BR16 cells, and the ER+/PR+/HER2− phenotype, belonging to MCF-7 cells (Fig. 3A). The gene discussed is ESR1; the disease is neoplasm.