BTN3A1 and parasitic infectious disease: Intracellular cytokine staining confirmed that Vγ9Vδ2 T cells produced most of this cytokine: parasite infection increased both the frequency of TNFα-positive Vγ9Vδ2 T cells (Fig 4J) and their iMFI (Fig 4K), whereas BTN3A1 inhibition returned both measures to baseline.