PLK2 and neurodegenerative disease: Among them, the up-regulated differentially expressed genes Tubb2a, Eno1, Atp2b1, Plk2, Map4, Pex5l, Fibcd1 and Pdzd2 were mainly involved in neuron to neuron synapse, vesicle-mediated transport in synapse, the calcium signaling pathway and neurodegenerative disease pathways, while the down-regulated differentially expressed genes Sh3gl2, Aldoa, Stxbp6 and Camk2g are mainly involved in ATP metabolism and the GnRH signaling pathway.