Moreover, incubation with exogenous lactate (lactate sodium) elevated IGF-1R levels in PI-resistant KAS-6/1 and U266 cells (Fig. 6I), suggesting that MUC20 decreased IGF-1R levels by inhibiting IGF-1R lactylation by increasing OXPHOS in PI-resistant MM cells. The gene discussed is MUC20; the disease is Miyoshi myopathy.