To determine whether the number of BT-ICs is associated with chemotherapeutic efficacy, we performed immunohistochemical staining to examine ALDH1 expression in 192 cases of invasive ductal carcinomas of the breast obtained by core-needle biopsy prior to pre-operative neoadjuvant chemotherapy, and evaluated the expression level following the criteria of a previous study [15]. Here, ALDH1A1 is linked to invasive ductal breast carcinoma.