These reductions in neuronal branching and brain size are in accordance with the postnatal microcephaly commonly observed in human CS patients (Christianson et al., 1999; Pescosolido et al., 2014), which is highly suggestive of a reduction in adolescent brain development when NHE6 function is reduced or ablated. The gene discussed is SLC9A6; the disease is Cowden syndrome 1.