Early Use of Tacrolimus: This study is about reducing Cytokine Release Syndrome (CRS), a condition where the immune system overreacts, after a special type of stem cell transplant. Hematopoietic stem cell transplantation is a process where patients get new, healthy blood stem cells from a donor. The study uses a medicine called Tacrolimus, started earlier than usual, to help prevent CRS. HLA-mismatched haploidentical allogeneic transplantation means getting stem cells from a donor who is a partial match to the patient.

• The study is for patients needing their first allogeneic transplant, not for those with severe heart, lung, liver, or kidney issues.
• Participants must have a related donor with a partial HLA match.
• Women in the study should not be pregnant and must use effective birth control.