Of the five patients with triple-negative breast cancer for ER, PR and HER2, a phenotype that has been reported to express cancer-stem cell and mesenchymal markers, and exhibit a more aggressive phenotype possibly associated with the EMT process and the downregulation of epithelial markers (Sarrió et al, 2008; Qi et al, 2010), two patients (B1, B5) had higher CTC counts using CellSearch than those obtained by ISET. Here, ERBB2 is linked to cancer.