Overall survival analysis according to ALDH1 expression pre- and post-chemotherapy. The Kaplan-Meier curves illustrate the prognostic significance of ALDH1 pre and post neo-adjuvant chemotherapy (NAC) in patients with locally advanced breast cancer. (A) Before chemotherapy, there was no significant difference in overall survival in ALDH1(−) vs. ALDH1(+) groups. (B) At the end of chemotherapy, patients who were ALDH1(−) had much better overall survival (100% five-year survival) compared to those who were ALDH1(+) (66.5% five-year survival). (P = 0.045, HR 3.75, 95% CI 1.03 to 14.42). ALDH1, aldehyde dehydrogenase-1.