The expression of PGC-1α and/or PGC-1β is reduced in conditions associated with skeletal muscle atrophy and perturbed metabolic function, such as aging (Ling et al., 2004; Rodriguez-Calvo et al., 2006; Joseph et al., 2012), denervation (Sandri et al., 2006; Sacheck et al., 2007), heart failure (Garnier et al., 2003; Vescovo et al., 2005), sepsis (Menconi et al., 2010), cancer cachexia and renal failure (Sandri et al., 2006), amyotrophic lateral sclerosis (ALS; Russell et al., 2013), insulin-resistance, and diabetes (Mootha et al., 2003; Patti et al., 2003). The gene discussed is PPARGC1B; the disease is amyotrophic lateral sclerosis.