For cells cultured under hypoxia, notably, genes associated to KEGG pathways involved in cytokine–cytokine receptor interaction and signaling pathways, including JAK-STAT, neurotrophin, and TNF signaling pathways, were upregulated, and KEGG pathways related to cell activation, such as focal adhesion and phagosome, metabolism pathways, glutathione metabolism, ECM–receptor interaction, proteoglycans in cancer, and some signaling pathways, including Rap1 and PI3K-Akt signaling pathways, were downregulated. The gene discussed is BDNF; the disease is cancer.