Protocol for a Pilot Phase IIa Randomized, Placebo-Controlled, Double-Blind, Crossover Study of Umbilical Cord-Derived Mesenchymal Stem Cells (UCMSC) for the Treatment of Relapsing-Remitting Multiple Sclerosis (RRMS):The MSCell Study. PPCR [Internet]. 2024 Nov. 28 [cited 2025 Apr. 9];10(3). Available from: https://journal.ppcr.org/index.php/ppcrjournal/article/view/332