TNFSF13B and Miyoshi myopathy: As the above experiments have demonstrated that S100A9 in neutrophils (a major source) promoted TNFSF13B signals in MM patients, we examined the regulation of TNFSF13B by measuring the surface presence of S100A9 on splenic neutrophils, macrophages, and monocytes after neutrophil depletion in mice (Figures 3A, B).