The present invention relates to the field of prophylaxis and therapy ofcancer. In particular there is provided a proteinindoleamine 2,3-dioxygenase (IDO) or peptide fragments here of that arecapable of eliciting anti-cancer immune responses.Specifically, the invention relates to the use of IDO or peptides derived herefrom or IDO specific T-cells for treatment of cancer.The invention thus relates to an anti-cancer vaccine which optionally may beused in combination with other immunotherapies andto IDO specific T-cells adoptively transferred or induced in vivo byvaccination as a treatment of cancer. It is an aspect of theinvention that the medicaments herein provided may be used in combination withcancer chemotherapy treatment. A further aspectrelates to the prophylaxis and therapy of infections by the same means asdescribed above. The use of IDO and immunogenicpep-tide fragments hereof in cancer and infection treatment, diagnosis andprognosis is also provided.
