Long non-coding RNAs are generally defined as transcripts more than 200 nucleotides but without protein-coding potential. This definition only distinguishes it from small non-coding RNAs, which can be further classified into more specific functional RNAs, such as miRNA and so on. Our understanding of lncRNA, especially in classification and function, is accruing but still lag expectations.
Molecular biology achieved revolutionary advances in the second half of the 20th century, and provided new insight into all aspects of biology. The transfer of genetic information, from DNA to RNA, to make a functional product, a protein. Life is codable. It appears that knowing the genomic DNA sequence is equivalent to knowing the code of life. When the Human Genome Project was finished, it was not as expected. Protein-coding sequences account for only a tiny fraction of the human genome, approximately 1.5%.