Pathogenic variants in MTM1 are associated with a severe, congenital muscle disorder called X-linked myotubular myopathy. Here, we aimed to assess the effect of mavacamten (myosin ATPase inhibitor) treatment in a mouse model for X-linked myotubular myopathy (Mtm1-KO) using the global untargeted proteomics approach. We used skeletal muscle tissue from Mtm1-KO mice and from WT mice, both treated and not treated with mavacamten.