Immunotherapy is a collective term for various different treatment approaches aiming to influence the activity of the human immune system. Oncology distinguishes between two different types of immunisation: active and passive immunisation. In active immunisation the patient receives administered substances to induce an immune response in their immune system. The immune response ideally leads to the death of the tumour cells, or at least to reduced tumour growth. In contrast, in passive immunisation the patient receives antibodies or antibody fragments. These selectively bind to tumour cells and so lead to their demise. In adoptive immunotherapy the patient’s leukocytes are removed and cultured ex vivo to be re-injected.