Microbial cues for a stem-like lymphoid niche.

While tertiary lymphoid structures (TLSs) broadly correlate with immunotherapy efficacy, their functional heterogeneity can translate into divergent clinical outcomes. In this issue of Cancer Cell, Hu et al. uncover a microbiota-orchestrated stem-like lymphoid niche in which CD70+ ILC2s sustain progenitor exhausted T cells, and their findings redefine the functional organization underlying TLS-associated antitumor immunity.