ARNT and Miyoshi myopathy: Taken together, these results suggest that as ARNT/HIF‐1β is overexpressed in high‐risk MM subtypes and RRMM acquired drug resistance, or induced by hypoxia in bone marrow microenvironment, it functionally contributes to drug resistance, thereby most likely accounting for poor response of patients with high‐risk MM or RRMM to the frontline agents such as bortezomib.