ALDH1A1 and clear cell adenocarcinoma: The log-rank test revealed that higher expression level of ALDH1 is associated with poorer prognosis with a significant difference in OS of patients with serous adenocarcinoma (P = 0.006) and OS of patients with clear cell adenocarcinoma (P = 0.047) than those of lower expression level of ALDH1 (Figure 6B).