The pathways enriched in different stages are slightly different, especially Stage IV of breast cancer, which has 18 specific enriched pathways, among which the PPAR signaling pathway, ECM-receptor interaction, tight junction, TGF-beta signaling pathway, NOD-like receptor signaling pathway, and other signaling pathways are mostly related to the metastases of breast cancer (Chen et al., 2012; Bao et al., 2019; Yang et al., 2019; Tang et al., 2017; Peng et al., 2016). The gene discussed is PPARA; the disease is breast cancer.