GRB2 and lissencephaly spectrum disorders: Members of this network include DISC1 binding partners such as Nuclear distribution protein nudE-like 1 (NDEL1), Fasciculation and elongation protein zeta-1 (FEZ1), lissencephaly (LIS1), Glycogen synthase kinase 3 beta (GSK3β), Girdin, Dixdc1 (Dixin), Growth factor receptor-bound protein 2 (Grb2), Ras homolog enriched in the brain 1 (Rheb1) and intracellular/extracellular signaling pathways, such as the AKT-mTOR, ERK, GSK3β, Wnt, NMDA-R, Reelin and GABA pathways (Fournier et al., 2010; Kang et al., 2011, 2015; Kim et al., 2012; Wu et al., 2013).