In our previous studies, we have demonstrated that binding immunoglobulin protein (BiP; or 78 kDa glucose‐regulated protein [GRP78]), a member of the heat shock protein 70 family, has prophylactic and therapeutic properties in the murine‐ collagen‐induced arthritis (CIA) model of RA when administered systemically as an extracellular protein 4, 5. Here, HSPA5 is linked to rheumatoid arthritis.