CDKN2A and neoplasm: LncRNAs can be divided into three types: well-studied tumor-suppressor genes (including LncRNA antisense noncoding RNA in the INK4 locus (ANRIL) and lncRNA maternally expressed gene 3 (MEG3)) [7,8], oncogenes, tumor-suppressor genes, and duplex lncRNAs according to their functions [9].