Thus, Ajani and coworkers showed that ALDH1 expression correlated with the presence of CSCs in EAC patients and predicted complete tumor responses (CTRs): thus, patients with CTRs exhibited very low ALDH1 levels, while patients resistant to chemo-radiotherapy treatment display high ALDH1 levels and had higher incidence of tumor relapse and cancer-related deaths [115]. This evidence concerns the gene ALDH1A1 and cancer.