SMN2 and myopathy: Unsurprisingly, we observed a larger number of significantly dysregulated myopathy and myogenesis genes in triceps of Smn−/−;SMN2 mice than in the more resistant quadriceps, some of which overlapped with the subset of genes aberrantly expressed in Fn14−/− mice and Tweak−/− mice (Fig. 6a, Table 1, Supplementary file 1).