question: Which protein is the main marker of Cajal bodies?
answer: Coilin is widely known as the protein marker of the Cajal body, a subnuclear domain important to the biogenesis of small nuclear ribonucleoproteins and telomerase, complexes that are crucial to pre-messenger RNA splicing and telomere maintenance, respectively The Cajal body has now regained the interest of biologists, due to the isolation of a protein marker, coilin.