AOC1 and neoplasm: We observed that AOC1 expression was noticeably higher in CRC liver metastatic tissues than in primary tumor tissues by IHC and qRT-PCR (Figures 2B, C), and significant associated with liver metastasis (p < 0.001) (Table 2), indicating that AOC1 is a potential biomarker for predicting liver metastasis of colorectal cancer.