Reasons for a trend to lower levels of GRP78 in bone marrow samples of MGUS patients compared to the NDMM and RRMM cohort could be the generally lower plasma cell infiltration in bone marrow and therefore, knowing that GRP78 is a stress-inducible chaperone, the smaller proportion of driver clones for transformation in symptomatic MM. Here, HSPA5 is linked to Miyoshi myopathy.