In a recent article published in Science, Dart and colleagues reported that colonic T cells expressing the Vγ4 T-cell receptor (TCR) interact with epithelial butyrophilin-like (BTNL) proteins BTNL3 and BTNL8 in healthy individuals, and they observed a depletion of Vγ4 T cells in inflammatory bowel diseases with renormalization associated with disease remission.1 This paper identifies the BTNL/Vγ4 axis as a new disease modifier in IBD.1 Here, BTNL8 is linked to inflammatory bowel disease.