In this paper we analyse the expression pattern of a zebrafish dlx4/6 enhancer/reporter construct in embryonic transgenic mice. We show that the pattern of LacZ/β-galactosidase in cells that tangentially migrate from the ganglionic eminences to the cerebral cortex is identical to that of various subpallial markers, namely Dlx and GAD genes, that are known to label this population. Because β-galactosidase activity persists long after expression of the Dlx genes and the transgene becomes undetectable, we were able to analyse the β-galactosidase-positive cell population of the mature cortex through X-gal staining and immunohistochemistry. We show that this population is largely identical with the adult cortical and hippocampal interneuron population, providing further evidence for their subpallial origin.