IL2 and neoplasm: Whereas cellular immune effector mechanisms are considered to be the most important mediators of IL-2 antitumour activity (Rubin et al, 1989; Donskov et al, 2002a), IFN-α in addition (Kosmidis et al, 1992; Tsavaris et al, 1996; Donskov et al, 2002a) is considered to exert antiproliferative (Grander et al, 1997) and differentiation-inducing effects on the tumour cells (Pfeffer et al, 1998).