HIF1A and myeloid sarcoma: Indeed, histological evidence exists for hypoxia in MS, including: increased endoplasmic reticulum (ER) stress and hypoxia-associated molecules in GM lesions [20], as well as hypoxia-like WM lesions [21] that show increased HIF-1α [22] and its downstream signaling molecules, such as vascular endothelial growth factor (VEGF) and glucose transporter 3 (GLUT-3) [23].