The spliceosome is a complex molecular machine found in the cells of eukaryotes. Its primary function is to remove non-coding regions, known as introns, from pre-messenger RNA (pre-mRNA) during the process of gene expression. This splicing process is essential for producing mature messenger RNA (mRNA), which carries the genetic information needed for protein synthesis. The spliceosome is composed of small nuclear ribonucleoproteins (snRNPs) and various proteins that work together to recognize specific sequences at the intron-exon boundaries. By accurately excising introns and joining exons, the spliceosome ensures that the final mRNA transcript is correctly formatted for translation into proteins.