It has been established that XBP1 and HIF1α co-operatively regulate HIF1α targets, including vascular endothelial growth factor-A (VEGF-A), phosphoinositide-dependent kinase 1 (PDPK1), glucose transporter 1 (GLUT1), and DNA-damage-inducible transcript 4 (DDIT4), in triple-negative breast cancer (TNBC) [147]. The gene discussed is DDIT4; the disease is triple-negative breast carcinoma.