Next, involvement of complement genes vital in phagocytosis (C1QA, C1QB, C1QC, C1R), which play a central role in immunity, response to infection, as well as synaptic pruning, further implicate the involvement of the immune system in ASD (Markiewski and Lambris, 2007; Dunkelberger and Song, 2010; Schafer et al., 2012). This evidence concerns the gene C1QB and infection.