Zfhx1b;Nkx2.1-Cre and Dlx1/2-/- mutants both fail to repress Nkx2-1 and Sox6, lose cortical interneurons, and accumulate MGE cells in their striatum. Coronal hemisections of the E15.5 telencephalon comparing gene expression in three rostral-to-caudal planes of section in controls (left side) and mutants (right side). In situ hybridization analysis of Nkx2-1 (A-C”), Lhx6 (D-F”), Sox6 (G-I”), NPY (J-L”) expression was assessed for control, Zfhx1b;Nkx2.1-Cre mutants and Dlx1/2-/- mutants. Asterisks show increased numbers of labeled cells in the striatum. X shows reduced number of Lhx6+ cells in cortex. Abbreviations: CGE: caudal ganglionic eminence; Cx: cortex; e: ectopia in region of the ventral striatum and central nucleus of the amygdala; GP: globus pallidus; LGE: lateral ganglionic eminence; MGE: medial ganglionic eminence; MZ: mantle zone; Str: striatum; SVZ: subventricular zone; VPd: ventral pallidum; VZ: ventricular zone. Scale bar equals 500μm (A).