Similarly SATB2, an evolutionary conserved chromatin remodeling gene that is activated in UL neurogenesis and required for callosal projection subtype determination (Section Deep-layer to Upper-layer Neurons and Figure 1F), is a key gene for the 2q33.1 microdeletion syndrome (Rosenfeld et al., 2009), and SATB2 haploinsufficiency has been associated with significant speech delay and cognitive defects (FitzPatrick et al., 2003; Leoyklang et al., 2007; Usui et al., 2013; Döcker et al., 2014). This evidence concerns the gene SATB2 and syndrome caused by partial chromosomal deletion.