There have 2 populations of T lymphocyte, αβ T cells, γδ T cells. They are distinguished by the expression of either an αβ T-cell receptor (TCR) or a γδ TCR. γδ T cells are a small population of lymphocytes, accounting for 0.5%–5% of overall T lymphocytes and have variable tissue distribution in the body. γδ T cells have been revealed to play a pivotal role in cancer progression through innate or adaptive immune responses. Learn more: gamma delta t cell line