Pharmacological or genetic blockade of FAAH has been shown to regulate pain and inflammation (Ahn et al., 2009; Cravatt et al., 2001), obesity and metabolic homeostasis (Brown et al., 2012; Touriño et al., 2010), and anxiety and depression (Gobbi et al., 2005; Kathuria et al., 2003), amongst many others. Here, FAAH is linked to obesity due to melanocortin 4 receptor deficiency.