DAO and neoplasm: Figures 6–8 shows that mRNA levels of BPGM (P < < 0.01), PSPH (P < 0.01), ACOT7 (P < 0.01) and CBS (P < 0.01) correlated positively with individual cancer stages, tumor grade, and nodal metastasis status. In contrast, DAO (P < 0.05) and AGXT2 (P < 0.01) mRNA levels were negatively correlated with individual cancer stages, tumor grade, and nodal metastasis status. In addition, there was also a negative correlation between individual cancer stages and tumor grade and the expression of CTH (P < 0.01), while there was no differential expression of CTH in different nodal metastasis statuses.