“…Tumour-specific immune responses which develop during early tumour growth decline and often disappear entirely (Deckers et al, 1973;Howell, Esber and Law, 1974;Youn, LeFrancois and Barski, 1973;Whitney, Levy and Smith, 1974). General immune responses, such as delayed hypersensitivity reactions to recall antigens and in vitro lymphocyte stimulation by mitogens and antigens, are also depressed in many cancer patients (Krant et al, 1968;Golub, O'Connell and Morton, 1974).…”