Tacrograf 2 Capsule belongs to a group of medicines known as immunosuppressants. Organ rejection happens when your immune system treats the new organ as an invader and attacks it. This medicine weakens your immune response (which usually fights infection) and reduces the chance of your body attacking the transplanted organ. It is used in combination with other medicines to make it much more likely that your transplant operation will be successful. You should continue taking the medicine and should not stop it until your doctor says so.