TNFSF13B and muscular dystrophy: Both forms of myositis displayed a significantly increased number of positive fibers in comparison to muscular dystrophies (BAFF 7%, CXCL-12 10%, and double positive 3%) and non-myopathic controls (BAFF 2.9%, CXCL-12 1.2%, and double positive 0%) (Figure 2B).