RecruitingPhase 2Drug trialA Randomized Study to Compare Post-transplant Cyclophosphamide, Sirolimus, Ruxolitinib and Post-transplant Cyclophosphamide, Sirolimus, Mycophenolate Mofetil to Prevent Graft Versus Host DiseaseThe goal of this clinical research study is to compare the effects of these drug combinations (cyclophosphamide, sirolimus, and MMF vs cyclophosphamide, sirolimus, and ruxolitinib) on the prevention of GVHD after a stem cell transplant.