<unk>  occurs when<unk> ed tissue is rejected by the recipient's immune system, which destroys the<unk> ed tissue.<unk>  can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after<unk> .
Transplant rejection
Graft-versus-host disease
Implant failure
Cardiac allograft vasculopathy
Liver regeneration
Injection fibrosis
Chronic allograft nephropathy
Tumor progression