The transcription factor Distal-less homeobox 1 (Dlx1) is required for the longevity of a subset of interneurons in the adult neocortex and hippocampus; Dlx1 knock-out mice show a selective loss of Som and calretinin-expressing (CR) cells and develop mossy fiber sprouting and recurrent seizures, supporting the relevance of Som cells to epilepsy (Cobos et al., 2005). This evidence concerns the gene DLX1 and epilepsy.