Dyslipidemia is improved by muscle-specific inhibition of MSTN signaling in A-ZIP mice. Serum triglycerides (A) and free fatty acids (FFA) (B) in male WT mice, Muscle-DN mice, A-ZIP mice, and A-ZIP, Muscle-DN mice at age 5 months (n = 7–9 for each genotype). Triglyceride concentration in gastrocnemius muscle (C) and liver (D) at age 5 months (n = 6). E: Representative liver histology by hematoxylin and eosin staining. Scale bar = 100 μm. F: Rate of oleic acid oxidation per mouse (n = 6–8 for each genotype). G: Rate of in vivo triglyceride synthesis obtained by measuring the accumulation of circulating triglycerides after inhibition of lipolysis by WR1339 (n = 5–9 for each genotype). Results are presented as mean ± SEM. Significance of repeated measures ANOVA is marked. *P < 0.05, **P < 0.01, ***P < 0.001. (A high-quality digital representation of this figure is available in the online issue.)