points to specific physical protein-protein interaction networks that may be key mediators of the underlying phenotypic differences, including the transcription factors PAX6 and SOX2, the chromatin regulator CTIP2 and its direct interactor NR2F1 (Nuclear Receptor subfamily 2, group F, member 1), a member of the nuclear hormone receptor family of receptors, and the calcium channel subunits CACNA1G and CACNA1E.