Previous in vitro and in vivo studies showed that in mice, loss of BIG2, a paralog closely related to BIG1, caused periventricular heterotopia (PH) and impairment of neural migration, which is explained by the BIG2-mediated regulation of Filamin A phosphorylation in NPCs [16, 51]. Here, ARFGEF1 is linked to Periventricular heterotopia.