UGT1A1 and neoplasm: The metabolic activity ratio was closely related to the protein reduction ratio between tumor tissues and the adjacent normal tissues (R2 = 0.725, P < 0.01) (Fig 3D, Table 3), and the accurate metabolic activities were significantly related to the protein and gene expression ratios of UGT1A1 (R2 = 0.700, P < 0.01; R2 = 0.593, P < 0.05) only in tumor tissues (Fig 3E, Table 4).