For example, several similarly expressed genes were identified in ExN1 and ExN3, including Kcnip4, Ncam2, and Zfpm2. Kcnip4 is correlated with Alzheimers disease (AD) and plays a key role in synaptic growth, synaptic plasticity, neuron proliferation, and neuronal differentiation.34 This evidence concerns the gene NCAM2 and Alzheimer disease.