CDH13 and attention deficit-hyperactivity disorder: Firstly, suppression of Cdh13 function in lower layer cortical neurons by RNAi leads to aberrant axonal projections (Hayano et al. 2014) and, secondly, Cdh13−/− mice display deficits in learning and memory due to alterations in neuron function in the hippocampus, similar to that observed in ADHD patients (Rivero et al. 2015).