IL2 and lung cancer: Briefly, regional lymph nodes with no metastasis obtained during surgery for the primary lung cancer were minced aseptically into blocks of about 1 mm3 and suspended in KBM-400 serum-free lymphocyte culture medium (Kojin Bio, Tokyo, Japan) with 400 IU interleukin 2 (IL2; Proleukin Chiron B.V., Amsterdam, Netherlands).