Even in patients with hyperdiploidy (HY), which occurs in up to 50% of MM and is associated with a more favourable prognosis [3], high DSG2 expression in MM PC identifies a subgroup with notably poorer survival (HR 3.21, 95% CI 1.04–9.92, P = 0.04). The gene discussed is DSG2; the disease is Miyoshi myopathy.