Specifically, label-free, directed mass spectrometry analysis (dMS) (30, 31) of proteins fractionated by sucrose-gradient centrifugation validated the comigration of components of the DGC in skeletal muscle from WT mice, but not the dystrophin-deficient mdx and delta-sarcoglycan-null (Sgcd-null) models of muscular dystrophy (32, 33). The gene discussed is SGCD; the disease is muscular dystrophy.