The serum interleukin-7(IL-7) level of MM patients was higher than that of normal controls (2.07 ± 0.71 vs. 1.62 ± 0.15 ng/L, P < 0.05), and was negatively correlated with the quantity of osteoblasts (r = -0.682, P < 0.01). Here, IL7 is linked to Miyoshi myopathy.