In breast cancer, the increase of the doxorubicin-dependent tumor immunogenicity via expansion of the pool of CD8+ tumor-infiltrating lymphocytes (TILs) is partially mediated by downregulation of stress-responsive enzyme HO1, which renders the breast cancer cells more susceptible to CD8+ cytotoxic T cells, possibly by counteracting the immunosuppressive effect of regulatory T cells (Treg) [146]. The gene discussed is HMOX1; the disease is breast cancer.