PMN-induced tumor destruction.

(A) Rejection area of subcutaneously injected tumor cells engineered to release IL-2 is massively infiltrated by polymorphonuclear leukocytes (× 630). (B) Electron micrograph showing that these are neutrophils at various stages of disorganization and that their exocytosed granules are in close contact with severely damaged or necrotic tumor cells (× 2750).