Ternary complexes of (a) human 9C1 TCR–CD1d–α-GalCer, (b) 9B2 TCR–CD1d–α-GalCer, (c) NKT15 TCR–CD1d–α-GalCer (PDB code 2PO6 (ref. 27) and (d) mouse XV19 TCR–CD1d–sulfatide (PDB code 4EI5 (ref. 36). Top panels depict an overview of each structure, middle panels illustrate the TCRs docking onto CD1d and lower panels show the TCR footprints on the CD1d–Ag molecular surface. The CD1d and β2-microglobulin molecules are coloured in light blue and light brown, respectively. 9C1 TCRα, brown; 9C1 TCRβ, light pink; 9B2 TCRα, light green; 9B2 TCRβ, purple; NKT15 TCRα, green; NKT15 TCRβ, cyan; XV19 TCRα, yellow; XV19 TCRβ, grey. The CDR loops are coloured as follows: CDR1α, aqua; CDR2α, purple; CDR3α, red; CDR1β, green; CDR2β, orange; CDR3β, blue. The α-GalCer and sulfatide are coloured in black and light brown sticks (top panel), or black and light brown spheres (middle and lower panels), respectively. In the middle panels, the centre of mass of the respective TRAV and TRBV variable domains are shown as black spheres. In the bottom panels, the molecular surface of CD1d is coloured in light grey.