Fig. 1.

Antigen release from dying tumor cells can activate immune responses—irradiation induces death of cancer cells. As these cells die, they are taken up by professional antigen presenting cells. These antigen presenting cells then travel to regional lymph nodes where they present antigen to T cells, initiating or potentiating an antitumor immune response. Activated tumor-specific T cells can then traffic to areas of tumor to participate in immune-mediated tumor killing.