In addition to studies of allogeneic MSCs from UCB or bone marrow, there has been an ongoing clinical trial using allogenic ABCB5-expressing MSCs (ABCB5+ MSCs) in patients with RDEB (ClinicalTrials.gov NCT03529877) since January 2019. The gene discussed is ABCB5; the disease is recessive dystrophic epidermolysis bullosa.