Much evidence indicates that C5a and C5aR play a critical role in neurodegenerative diseases (Yanamadala and Friedlander 2010; Zhou et al. 2009; Quadros and Cunha 2016; Barnum 2002; Farkas et al. 2003), and the C5a has a number of effects on neurons in vitro (Mukherjee and Pasinetti 2001; Farkas et al. 1998; Pavlovski et al. 2012). The gene discussed is C5AR1; the disease is neurodegenerative disease.