Latent tumor killers awakened

A single-cell atlas of bone marrow T cells from patients with marrow-resident malignancies revealed tumor-reactive populations existing in a state of latent competence rather than terminal exhaustion. Kehl et al. defined a 15-gene signature that reliably identifies this subset, which expands upon immunotherapy treatment and predicts clinical responses. The findings reframe the understanding of anti-tumor immunity in the bone marrow microenvironment, suggesting that latently competent T cells represent a therapeutically actionable reservoir.