CHOP and BiP levels are elevated in cells that play a central role in MS pathology, including T-cells, microglia, astrocytes and OLs; this is in conjunction with increased expression of multiple UPR markers, such as phosphorylated PERK, phosphorylated-eIF2α, BiP, and CHOP [12,43,45]. The gene discussed is HSPA5; the disease is myeloid sarcoma.