CASP3 and myopathy: Because HSPB5 (R120G) mutations in desmin-related myopathies are known to induce apoptosis by promoting protein aggregation [37], overexpression of HSPB5 (R120G) also confirmed the loss of the suppressive effect on ER stress-induced caspase 3 activation (HSPB5 (WT) vs. HSPB5 (R120G); † p < 0.05), as well as the HSPB5 (3A) triple mutation.