Although larger gene or mutation panels are available, as more than 93% of mutations were detected in TP53, PIK3CA, or ESR1 genes, and also predicted poor OS in MBC, we suggest that this assay can accurately detect mutations of clinical importance, such as in ESR1, where emergence of mutations heralds resistance to aromatase inhibitors.22,23 Of interest, three patients with TNBC had ESR1 mutations detected, suggesting the presence of a small ER-positive clone; comparison with circulating tumor cells and or metastatic tissue biopsy would be helpful in these patients to explore tumor evolution. The gene discussed is CYP19A1; the disease is neoplasm.