PPARGC1A and neoplasm: Compared to the normal tissue in the TCGA cohort, ACOX2 (P < 0.001), PTGS1 (P < 0.001), PTGS2 (P < 0.001), and PPARGC1A (P < 0.001) were downregulated, while HAO1 (P < 0.001) was upregulated in tumor samples (Figure 6A).