A2M and Duchenne muscular dystrophy: In particular, Collagen alpha‐1(VI), alpha‐2(VI), and alpha‐3(VI) chains, Collagen VI (COL6A1, COL6A2, and COL6A3 chains), Alpha‐2‐macroglobulin (A2M), and Fibrinogen gamma chain (FGG) were increased in DMD vs. BMD (Figure2A).