Conclusion
The present study shows that unique ASV derived from receptors that play key roles in angiogenesis – namely, VEGF receptor type 1 and, for the first time, Tie1 – can markedly reduce arthritis severity. More broadly, our results demonstrate that ASV are a source of novel proteins with therapeutic potential in diseases in which angiogenesis and cellular hyperplasia play a central role, such as rheumatoid arthritis.