Approved by the FDA in 2024 for steroid-refractory acute graft-versus-host disease (SR-aGVHD) in pediatric patients, this cell therapy exploits the immunomodulatory and anti-inflammatory properties of MSCs.118 The cells secrete bioactive molecules such as transforming growth factor-β (TGF-β), interleukin-10 (IL-10), and prostaglandin E2, which collectively suppress T-cell proliferation and shift the immune response toward tolerance.119 Additionally, MSCs promote tissue repair and inhibit fibrosis, which is crucial in the context of GVHD. This evidence concerns the gene IL10 and acute graft versus host disease.