CD8A confirms CD8⁺ T cell lineage identity. PRF1 (perforin-1) and GZMB (granzyme B) are cytotoxic effector molecules stored in cytotoxic granules and are characteristic of cells with cytotoxic activity. CX3CR1 (fractalkine receptor) shows enriched expression in terminally differentiated cytotoxic T cells and is associated with effector memory and tissue-patrolling states. Together these markers identify cytotoxic CD8⁺ T cells and distinguish them from naive and memory CD8⁺ T cell populations.
