For the downregulated hub genes, the expression of AOX1 (Figure 4H), ALDH1A1 (Figure 4I), ADH1B (Figure 4J), MAOB (Figure 4K) and ALDH1A2 (Figure 4L) were significantly suppressed in ovarian cancer compared with normal samples, and there were no significant differences in the expression of KDR, HSD17B6, MANOG, CYP3A5 and FGF13 between ovarian cancer samples and normal samples (Supplementary Figure S1D-H). This evidence concerns the gene ALDH1A2 and ovarian cancer.