EIF2AK3 and Miyoshi myopathy: While current research fails to provide a clear-cut answer with regard to the underlying mechanisms of PERK signaling in controlling the UPR commitment to survival or death, emerging data suggest that cell fate decision under ER stress may be determined by the intensity and duration of UPR signal in concert with innate immune response and surrounding bone marrow microenvironment of MM cells [53, 54].