is a primate-specific long noncoding RNA with emerging roles in homeostasis and pathophysiology. Elevated blood levels of have been observed in patients with cardiovascular disease and several cancers, where it is correlated with poor clinical outcomes. Like many lncRNAs, accumulates in both the nucleus and the cytoplasm, and it assumes distinct functions in each of these cellular compartments. In the nucleus, sequesters a transcriptional repressor complex to activate interferon-stimulated gene expression and antiviral immunity. In the cytoplasm, competitively inhibits microRNAs involved in cholesterol efflux and cell cycle regulation, thereby impacting gene pathways involved in reverse cholesterol transport, HDL biogenesis, and tumor growth. In this review, we detail the multifaceted functions of in cholesterol metabolism, innate immunity, and cancer progression. We also explore the potential molecular mechanisms that govern its expression and dynamic subcellular localization, which may be key to its functional versatility. Advancing our understanding of the regulatory networks and cellular environments that shape activity will be critical for assessing its promise as a therapeutic target and diagnostic biomarker.