This review focuses on the emerging roles of long non-coding RNAs (lncRNAs) in tumor biology. LncRNAs, which are transcribed from the human genome but do not code for proteins, have been found to be deregulated in various cancers and show tissue-specific expression. Functional studies have revealed a broad spectrum of mechanisms by which lncRNAs, such as HOTAIR, MALAT1, ANRIL, and lincRNA-p21, exert their functions. These mechanisms include chromatin modification, transcriptional regulation, and post-transcriptional processing. The review links the cellular processes influenced by lncRNAs to the hallmarks of cancer, providing an ncRNA perspective on tumor biology. This perspective should stimulate new research directions and therapeutic options, considering lncRNAs as novel prognostic markers and therapeutic targets. The review also discusses specific lncRNAs and their roles in sustaining proliferative signaling, evading growth suppressors, enabling replicative immortality, activating invasion and metastasis, inducing angiogenesis, and resisting cell death. Examples include SRA, PCAT-1, ANRIL, GAS5, lincRNA-p21, TERRA, MALAT1, and HOTAIR, which have been implicated in various cancer types and processes. The review highlights the importance of lncRNAs in cancer development and suggests future research directions to better understand their roles in carcinogenesis and metastasis.This review focuses on the emerging roles of long non-coding RNAs (lncRNAs) in tumor biology. LncRNAs, which are transcribed from the human genome but do not code for proteins, have been found to be deregulated in various cancers and show tissue-specific expression. Functional studies have revealed a broad spectrum of mechanisms by which lncRNAs, such as HOTAIR, MALAT1, ANRIL, and lincRNA-p21, exert their functions. These mechanisms include chromatin modification, transcriptional regulation, and post-transcriptional processing. The review links the cellular processes influenced by lncRNAs to the hallmarks of cancer, providing an ncRNA perspective on tumor biology. This perspective should stimulate new research directions and therapeutic options, considering lncRNAs as novel prognostic markers and therapeutic targets. The review also discusses specific lncRNAs and their roles in sustaining proliferative signaling, evading growth suppressors, enabling replicative immortality, activating invasion and metastasis, inducing angiogenesis, and resisting cell death. Examples include SRA, PCAT-1, ANRIL, GAS5, lincRNA-p21, TERRA, MALAT1, and HOTAIR, which have been implicated in various cancer types and processes. The review highlights the importance of lncRNAs in cancer development and suggests future research directions to better understand their roles in carcinogenesis and metastasis.