Any alterations, for example, in chronic inflammation, tumorigenesis, or pathogen infection, can lead to the accumulation of unfolded/misfolded proteins in the ER, which causes disorder of the ER homeostasis and can trigger the expression of chaperones, such as GRP78 (eg 78 kDa glucose‐regulated protein [GRP78]), calreticulin and calnexin.9 This evidence concerns the gene HSPA5 and infection.