Recently there have been explosive discoveries of new long noncoding RNAs (lncRNA) obtained by progress in the technology of second-generation sequencing. Genome scale analysis of transcriptome, in conjunction with studies on chromatin modifications at the epigenetic level, identified lncRNAs as a novel type of noncoding transcripts whose length is longer than 200 nucleotides. These transcripts are later found as major participants in various physiologic processes and diseases, especially in human cancers. LncRNAs have been found to function as novel types of oncogenes and tumor suppressors during cancer progression through various mechanisms, which endow them with the potential of serving as reliable biomarkers and novel therapeutic targets for cancers. .