In multiple myeloma (MM) patients’ cells and in RPMI-8226 and U266 MM cell lines, JAK1 and JAK2 resulted in overexpression, and upon treatment with ruxolitinib and bortezomib, these cells presented 50% of cells in late apoptosis, a reduction in antiapoptotic gene expression, and a higher number of cells in the SubG0 phase. The gene discussed is JAK1; the disease is Miyoshi myopathy.