In most mouse models of HD, the abundance of BDNF protein (Duan et al., 2003, 2008; Saydoff et al., 2006; Simmons et al., 2009; Xie et al., 2010) and Bdnf mRNA is decreased in mutant compared to normal mice in cortex, striatum and hippocampus (Zuccato et al., 2005; Pang et al., 2006; Zajac et al., 2010). The gene discussed is BDNF; the disease is Huntington disease.