CD3D and CD3E are components of the T cell receptor signaling complex, confirming T cell lineage identity. FOXP3 is a transcription factor required for regulatory T cell specification and function, and is the defining marker of this population. TIGIT and CTLA4 are inhibitory receptors enriched in regulatory T cells, reflecting their immunosuppressive function. Together these markers reliably identify regulatory T cells (Tregs) and distinguish them from conventional CD4⁺ and CD8⁺ T cell populations.
