Antibodies that target the ERS-related protein GRP78 can be detected in the blood of SLE patients, and the expression of GRP78 and XBP1 is increased in plasma cells that secret antibodies, suggesting that the ERS may promote the differentiation of B cells into plasma cells to increase the secretion of antibodies [40, 41]. Here, HSPA5 is linked to systemic lupus erythematosus.