HCG18 and Alzheimer disease: The analysis of ceRNA regulatory network showed that lncRNA NEAT1, XIST, HCG18 and KCNQ1OT1 may competitively bind hsa‐let‐7c‐5p, hsa‐miR‐107, hsa‐miR‐129‐2‐3p and hsa‐miR‐214‐3p and regulate Atp6v0b, Atp6v1e1, Atp6v1f and Syt1 in AD brain.