Although incompletely understood, it seems that the abscopal effect represents the distant effect of in-situ, tumor-specific immunostimulation, through activation of antigen-presenting cells following the local release of tumor-associated antigens (TAAs) after RT, leading to the activation of T CD8+ lymphocytes and consequent tumor destruction by cell-mediated immunity (22, 48, 49, 57). The gene discussed is CD8A; the disease is neoplasm.