Moreover, the HCC-related functional module included the chemical carcinogenesis, p53 signaling pathway, and apelin signaling pathway, and the immune inflammatory system-related functional module was involved by PI3K-Akt signaling pathway, which has been reported to be highly expressed in HCC patients and closely related to cancer cell proliferation, survival, invasion and angiogenesis [22]. Here, APLN is linked to hepatocellular carcinoma.