We classified 1501 plasma cells in MM into four distinct cell subsets, C1 IGHA1+ Myeloma cells, C2 IGHG1+ Myeloma cells, and C3 IGHG4+ Myeloma cells, in order to better understand the characteristics of plasma cells in MM (Figure 3A). The gene discussed is IGHA1; the disease is Miyoshi myopathy.