Given this background and since the NRG-1/ErbB pathway and L-arginine are implicated in increasing utrophin expression in experimental models of muscular dystrophy [10, 11, 18–21], the aim of this study was to evaluate the effect of L-arginine in the activation of NRG-1/ErbB pathway and utrophin expression in C2C12 cells and to study the participation of ADAM17 in this process. The gene discussed is UTRN; the disease is muscular dystrophy.