Tumors derived from immunodeficient mice are highly immunogenic. Seventeen MCA-induced sarcomas from wild type mice (panels a and c) and twenty MCA-sarcomas from RAG2^-/- mice (panels b and d) were each injected into five member groups of either immunodeficient RAG2^-/- mice (panels a and b) or naive immunocompetent wild type mice (panels c and d). Tumor growth was monitored by daily measurement of tumor size [adapted from (49)].