(A) (A1) Intergenic lncRNAs are located between two protein-coding genes, (A2) intronic lncRNAs are located within one of the introns of a protein-coding gene, (A3) bidirectional lncRNAs are situated on the opposite strand of the protein-coding gene, within 1 kb of the promoter of this gene, and are transcribed in the opposite direction of this promoter, (A4) enhancer lncRNAs are located in the enhancer regions of the protein-coding gene, (A5) sense lncRNAs sit within the same strand as the protein-coding gene, can span multiple introns or exons and are transcribed in the same direction as the coding gene, (A6) antisense lncRNAs are located on and transcribed from the opposite strand of a protein-coding gene. (B) (B1) LncRNA can act as scaffold linking different proteins, such as different subunits of chromatin modifying complex, required for a synchronized action, (B2) LncRNA can recruit or guide proteins, such as transcription factors, to a specific site on the DNA, (B3) enhancer lncRNAs can link enhancer and promoter regions of genes through chromosomal looping, and (B4) decoy lncRNAs can lead astray the target proteins from DNA or can bind to and compete with miRNAs.