Chronic Graft-versus-Host Disease (GVHD) is a complication that affects many hematopoietic stem cell transplant (HSCT) survivors; it occurs when the new cells from a transplant attack the recipient's body. The current standard GVHD prophylaxis regimen for patients with hematologic malignancies undergoing HSCT involves a combination of immunosuppressive agents given for the first 6 months after transplant. Often, patients develop GVHD and continue on these agents for much longer periods. The combination of calcineurin inhibitors (tacrolimus and cyclosporine A) with methotrexate (MTX) is the most common GVHD prophylaxis used worldwide in the context of myeloablative conditioning transplants. This regimen demonstrates better control of acute GVHD, but is less effective against chronic GVHD. Management of chronic GVHD remains a challenge and it has become a significant health problem in transplant survivors with more frequent use of mobilized peripheral blood stem cells. Additionally, several issues arise with the standard approach including various toxicity symptoms and side effects, increased risk of thrombotic microangiopathy due to CNI, no prevention of other infectious diseases, and no prevention for disease relapse.