ELFN1 and attention deficit-hyperactivity disorder: The two broadest H3K4me3 peaks in PFC neurons, extending >12 kb, were ELFN1 (extracellular leucine rich repeat fibronectin domain 1), implicated in epilepsy and attention-deficit hyperactivity disorder and essential for GABAergic signaling in subsets of cortical and hippocampal interneurons54, 55 and LINC00966, a poorly characterized noncoding transcript that encodes within its sequence microRNA 124-2, targeting homeobox transcription factor Dlx5 (ref. 56) with a critical role in cortical interneuron development57 (Figure 2d).