GRIK4 and early-onset autosomal dominant Alzheimer disease: Both GRIK4 (glutamate ionotropic receptor kainate type subunit 4) and UNC79 (unc-79 homologue, NALCN channel complex subunit) have biased expression in the brain and encode ion channel subunits, and it is conceivable that their dysfunction may contribute to altered synaptic plasticity, learning, and development in Alzheimer’s disease [21].