HSPA5 and Miyoshi myopathy: A recent study has demonstrated that PI resistant MM cells exhibit increased expression of Glutathione S-transferase P (GSTP), which mediates SSG of ER resident proteins, such as binding immunoglobulin protein (BiP), calnexin, calreticulin, endoplasmin, sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), and other protein-folding and redox-active proteins, thereby regulating their activities (279–281).