Distribution and function of human long-lasting T cells in aging and non-small cell lung cancer.

T lymphocytes, essential components of the adaptive immune system, orchestrate pathogen-specific responses and long-term immunological memory through heterogeneous subsets with distinct functional properties and spatial distributions. This comprehensive review delineates the origin, distribution, and functional specialization of long-lasting T cell subsets-naive T cells (Tn), stem cell-like memory T cells (Tscm), central memory T cells (Tcm), effector memory T cells (Tem), and tissue-resident memory T cells (Trm)-across physiological and pathological contexts, with a particular focus on aging and non-small cell lung cancer (NSCLC). We further dissect the complex intertwined mechanisms underlying immunosenescence and NSCLC pathogenesis. Elucidating how aging remodels T cell maintenance, tissue tropism and metabolic adaptation provides a conceptual framework for developing targeted therapeutic interventions against NSCLC.