Lastly, we validated the potential of PTCH1 and CTNNB1 as predictive biomarkers for neoadjuvant chemotherapy in ER+/HER2- breast cancer patients, by performing Cox Proportional Hazards Regression in two additional treatment arms: patients with no systemic therapy and patients who underwent endocrine therapy (Table 6). The gene discussed is ERBB2; the disease is breast carcinoma.