Pangraf is the generic name for the immunosuppressant drug tacrolimus, which is used to prevent rejection in organ transplant patients. It works by inhibiting calcineurin and reducing T-lymphocyte activity in the immune system, effectively weakening the body's defenses to allow acceptance of the transplanted organ. Pangraf capsules are produced using a mutated strain of Streptomyces tsukubaensis bacteria through submerged aerobic fermentation. Close monitoring of blood pressure is recommended for patients taking this medication.