SETDB1 depletion in mouse tumours derepresses immunostimulatory genes and TE-encoded retroviral antigens and MHCI peptides, which will increase CD8+ T cells and p15E-specific CD8+ T cells expressing canonical cytotoxicity genes, triggering cytotoxic T cell responses and sensitizing tumours to ICB (Griffin et al., 2021). The gene discussed is CD8A; the disease is neoplasm.