Nature Metabolism, Published online: 09 December 2025; doi:10.1038/s42255-025-01415-6Dietary restriction promotes the expansion of effector T cells via ketone bodies, which enhances anti-tumour immunity and synergizes with immunotherapy in mice.

Exploiting specific T cell subset properties bears potential for T cell therapies but is complicated by inconsistencies in T cell subset definitions and markers. Here, we discuss causes for the definition and classification complexities to provide a handle for how to navigate the T cell subset jungle.

Chemotherapy combined with immune checkpoint blockade has shown clinical activity in breast cancer. Response, however, occurs in only a low proportion…