The results of the present study demonstrated that tumour burden suppressed anti-vaccinia cellular immunity and that the oral administration of JTT improved the impairment of antiviral CD8+ T cell immunity in tumour-bearing mice (Figures 1(b) and 1(c) (left)), but not in immune-competent tumour-free mice (Figures 1(d) and 1(e)). The gene discussed is CD8A; the disease is neoplasm.