Pathological studies have shown that the vulnerability of plaques affects outcomes in patients with atherosclerosis (AS),a chronic inflammatory disease and common cause of morbidity and mortality worldwide.Although emerging technologies have enabled early diagnosis of AS with high-risk vulnerable plaques,more accurate and noninvasive diagnostic methods are urgently required.To this end,molecules involved in genetic or epigenetic regulation of the vulnerability of atherosclerotic plaques have been extensively studied.Here,we evaluated long noncoding RNA (IncRNA) variability by microarray assay in murine aortic endothelial cells (MAECs) bearing vulnerable plaques and identified the novel functional IncRNA UC.98,whose expression patte was associated with the vulnerability of atherosclerotic plaques.Consistent with this,clinical statistics comparing the peripheral blood specimens from sets of patients with AS with or without vulnerable plaques confirmed the linear relationship between the expression patte of UC.98 and plaque instability.Moreover,MTT assays and weste blot analysis showed that silencing of intrinsic UC.98 in MAECs not only suppressed cell proliferation but also decreased the expressions of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1,thereby inactivating the nuclear factor-κB pathway.In conclusion,our results highlighted the pivotal role of UC.98 in regulating the vulnerability of plaques during AS progression and suggested that UC.98 may be a biomarker of the early diagnosis and prognosis of AS with vulnerable plaques and a potential therapeutic target for slowing AS progression.