muMt–/– tumour tissues were enriched in infiltrating CD8+ T cells with enhanced cytotoxic and inflammatory properties (Fig. 3b, c, and Extended Data Fig. 4a–c), which was suppressed in muMt–/– mice with GABA implants (Fig. 3b, c, and Extended Data Fig. 4a–c). The gene discussed is CD8A; the disease is neoplasm.