The expression of hypoxia-inducible factor (HIF)-1α was upregulated in myeloma cells under hypoxic conditions (2% O2 and 1% O2), and the upregulation of HIF-1α was more evident in myeloma cells cultured for 4 weeks compared with those cultured for 2 weeks (Figure 1A). The gene discussed is HIF1A; the disease is plasma cell myeloma.