We selected the genes that were differentially expressed in SEPN1 KO and WT animals (pKO < 0.01), and then used pathway enrichment analysis to reveal the strong enrichment of the TGF-beta, a cytokine resident in the ECM whose hyperactivation is a known cause of myopathies and other muscle disease19 (Fig. 2A and Sup. The gene discussed is SELENON; the disease is myopathy.