Kits to assess the risk of tumor progression

The present invention is based on the discovery antigen-presenting cells (APCs) may be generated to have predetermined levels of expression of the intracellular enzyme, indoleamine 2,3-dioxygenase (IDO). Because expression of high levels of IDO is correlated with a reduced ability to stimulate T cell responses and an enhanced ability to induce immunologic tolerance, APCs having high levels of IDO may be used to increase tolerance in the immune system, as for example in transplant therapy or treatment of autoimmune disorders. Also disclosed are kits for assessing the relative risk of tumor progression in a subject. For example, disclosed are kits for assessing the relative risk of tumor progression in a subject and having reagents for detection of the enzyme indoleamine 2,3-dioxygenase (IDO) in a sample of tissue from a tumor or tumor draining lymph node from a subject, wherein the reagents are packaged in at least one individual container. The kits may include reagents for detection of cell surface or immunohistochemical markers associated with high IDO expression by APCs such as DO, CD123, CD11c or CCR6.