So it also stabilizes the mRNA molecule and AIDS in transport across the nuclear membrane of the nucleus of the cell. Now let's move on to the second type of process, second type of post transcriptional modification that takes place in the nucleus known as the poly and ventilation of the three and tail. So before the nucleus or before the pre mRNA actually leaves our nucleus, our tail has to actually be removed. So a small section of the tail of the premna is removed and instead we add many adenosine nucleotides. And this tail, this three and tail is now known as the polyatail. So in this type of post transcriptional modification the three end of the precursor mRNA is removed and a series of adenosine nucleotides are added.