FLRT3 and attention deficit-hyperactivity disorder: Because intercellular adhesion events mediated by FLRT3 expression exhibited deficits across all ADHD-related Lphn3 receptor variants and considering the intrinsic G13 coupling deficiency expressed by these variants, we sought to elucidate the modulation of G13 protein signaling pattern emanating from such ligand-dependent adhesive junctions by implementing a hybrid assay involving matrix-plated cell aggregation samples (Fig. 5).