RNA processing is a crucial step in the expression of genes. After a gene is transcribed into a precursor messenger RNA (pre-mRNA), this molecule undergoes several modifications. These include the addition of a 5' cap, which protects the RNA and helps it bind to ribosomes, and a poly-A tail at the 3' end, which stabilizes the RNA and aids in its export from the nucleus. Additionally, introns, non-coding regions of the pre-mRNA, are removed through a process called splicing. The remaining coding sequences, known as exons, are then joined together to form a mature messenger RNA (mRNA). This processed mRNA can then be translated into proteins, which perform various functions in the cell.