For example, in the forebrain, a risk allele for autism spectrum disorder (ASD) in the MET promoter, which reduces MET transcript and protein levels (Campbell et al., 2006, 2007), is correlated with altered circuit function in typical and ASD human populations (Rudie et al., 2012) and in gray matter growth (Hedrick et al., 2012). Here, MET is linked to autism spectrum disorder.