Immune signaling as a determinant of cellular identity and tissue function.

Immunology has traditionally interpreted tissue pathology through models centered on immune-mediated cytotoxicity. In this prevailing model, functional decline is considered a downstream consequence of cell death and irreversible loss of cellular mass. Increasing evidence across metabolically active tissues challenges this paradigm by demonstrating that immune-derived signals exert potent regulatory effects on cellular identity that are independent of overt cytotoxicity. Cytokines, interferons, and inflammatory mediators directly engage transcriptional, epigenetic, and stress-response networks that sustain differentiated states. This engagement leads to suppression of lineage-defining gene programs, destabilization of identity-enforcing regulatory circuits, and sustained impairment of specialized function while cellular viability is preserved. In this Perspective, we propose a conceptual reframing in which immune systems are considered continuous regulators of cellular identity stability rather than solely as determinants of cell survival. The process becomes stabilized through epigenetic remodeling and generates persistent dysfunctional states that may be variably reversible depending on the duration and intensity of immune exposure. The proposed framework distinguishes immune-induced plasticity from epigenetically fixed identity failure. By repositioning immune instruction of cellular identity as one of the central mechanisms of disease pathogenesis, this framework opens new conceptual avenues. It further emphasizes therapeutic strategies focused on restoring tissue function through the reestablishment of differentiated states.