To this end, diagnostic HER2 + BC biopsies from selected neoadjuvant-treated HER2 + BC patients who did or did not achieve pCR, identified as the pCR Yes (n = 18) and pCR No (n = 18) cases, respectively (Table 2), were subjected to in situ assessment of the percentage of HER2 + cells also expressing CD36 (CD36 + cells %) or CD44v6 (CD44v6 + cells %) (Fig. 2A), a specific CD44 isoform enriched in EMT-like stem cells [40]. This evidence concerns the gene ERBB2 and breast cancer.