BTNL3 and inflammatory bowel disease: First, because Vγ4+ cells appear highly sensitive to BTNL3+BTNL8 engagement, the reduced levels of BTNL3+BTNL8 expression reported for IBD (15, 46) are not necessarily causal to Vγ4+ cell dysregulation, by contrast to either BTNL loss-of-function in donors homozygous for BTNL8*3 or the IBD-associated cytokine milieu.