The number of either TIM-3+ PD-1+ CD8+ T cells or LAG-3+ PD-1+ CD8+ T cells was significantly correlated with tumor volume following repeated stimulation of D1-receptor-expressing neurons in the medial shell of the nucleus accumbens in mice transplanted with LLC (Fig. 5c, f, Pearson's correlation coefficient test). The gene discussed is CD8A; the disease is neoplasm.