BTN3A1 and cancer: This notion is supported by the finding that intratumoral γδ T cell is the most predictive immune signature of improved outcomes across 25 cancers.[25] Furthermore, Vγ9Vδ2 subset, the predominant human circulating γδ T cell subpopulation that can be activated by PAg overproduced by tumor cells in a butyrophilin 3A1 (BTN3A1) dependent manner, has been frequently selected for ACT in a variety of cancers.[22, 23, 24, 26] Additionally, Vγ9Vδ2 T cells can interact with αβ T cells, and thereby modulate immune responses through multiple mechanisms.