TNFSF10 and rheumatoid arthritis: TNFSF10, also known as TNF-Related Apoptosis Inducing Ligand (TRAIL), encodes a protein that induces apoptosis of tumor cells but is also of interest in RA as it has been thought that TNFSF10 might induce apoptosis of hyperplastic synoviocytes and reduce immune cell hyperactivity thus providing a protective effect to the joint.