This study published in PLOS ONE evaluates the safety and effectiveness of using mesenchymal stem cells (MSCs) as a treatment for rheumatoid arthritis (RA). By analyzing clinical trials involving adult RA patients, the researchers aimed to determine whether MSCs, derived from sources like bone marrow and umbilical cords, could reduce inflammation, repair joint damage, and improve symptoms such as pain and stiffness. The study concluded that MSC therapy shows promise in reducing disease activity and improving patient quality of life, with minimal side effects observed. However, more large-scale trials are recommended to confirm these findings.