MAOB and neoplasm: Subsequently, we analyzed 32 paired tumor-normal tissue samples for NE synthase and degrading enzyme mRNA expression in TCGA database, and the MAOA (p ≤ 0.001) and MAOB (p ≤ 0.001) mRNA levels showed significantly higher expression in normal tissues than in the paired tumor tissues (Figures 2(g) and 2(h)).