ACOX2 and esophageal squamous cell carcinoma: An investigation of genes related to fatty acid β-oxidation, such as PPAR, CPT1, and ACOX2, revealed that ACOX2 and PPAR were decreased in ESCC tissues but that CPT1 was upregulated (P < 0.0001; P < 0.05; P < 0.05) (Fig. 5M–O).