CD1D and neoplasm: Type I NKT cells are reactive to the glycolipid α‐galactosylceramide (α‐GalCer), a strong inducer of anti‐tumour immunity in mice.9, 10, 11, 12 When loaded on CD1d‐tetramers, CD1d/α‐GalCer forms a stable reagent that can be used for detection of type I NKT cells.13, 14 This has been instrumental for generating detailed information on type I NKT cells and has helped to establish an immunoregulatory role of these cells.