CORRESPONDENCE

Invariant natural killer T (iNKT) cells consti-tute a peculiar T lymphocyte subset, which is characterized by the coexpression of NK mark-ers and an invariant TCR- chain (V14J18 in mouse or V24J18 in human), which pairs with a restricted number of TCR- chains (V8, V7, and V2 in mice and V11 in human). iNKT cells recognize glycolipid antigens, such as -galactosylceramide (-GalCer), presented in the context of CD1d molecules (1). iNKT cells develop in the thymus from CD4+ CD8+ double-positive (DP) cells that have randomly rearranged the semiinvariant TCR and ar