The upregulation of SOX2 following increased NEDD9 transcription under hypoxia leads us to conclude that hypoxia-induced HIF-1α expression and breast cancer cell migration at least in part, involves a cascade of novel signaling events, including SOX2 expression, activation of NEDD9 transcription and expression, and subsequent activation of Rac1. The gene discussed is SOX2; the disease is breast cancer.