Flow cytometric analysis was performed to detect the Th17 cells in peripheral blood (CD3+ CD8– IL-17A+) accounted for the proportion of CD3+ CD8- lymphocytes in 58 MM patients and 20 healthy donors (Figure 2A-2G), the Th17 cells in the incipient and relapsed MM patients were significantly higher than healthy donors (HD) (0.95 ± 0.10% vs. 0.34 ± 0.03%, p < 0.001; 0.78 ± 0.14% vs. 0.34 ± 0.03%, p < 0.01; Figure 2H). The gene discussed is CD8A; the disease is Miyoshi myopathy.