The top hub genes mainly contained replication protein, DNA replication helicase, replication factor, WRN RecQ like helicase and exonucleases in gastric cancer, Apolipoproteins, lipase C, phospholipase A2, and cholesteryl ester transfer protein in lung cancer, minichromosome maintenance protein in breast cancer, and ribosomal proteins in ovarian cancer. The gene discussed is CETP; the disease is gastric cancer.