Adherent lymphokine-activated killer (A-LAK) activity has been recently differentiated in recombinant interleukin-2 (rIL-2) activated PBL. A pilot study on A-LAK + rIL-2 injection into the post-surgical cavity of glioblastoma-operated patients is ongoing. Preliminary data support the feasibility of this technique, which may improve the antitumor response of the host.