High CD4⁺/CD4^- iNKT cell ratio in human thymus. iNKT cells were identified in freshly isolated thymocytes as 6B11/Vβ11-double–positive events after collecting 2 to 3 × 10⁶ events (left), and CD4/CD8 distribution was analyzed within iNKT subset (right). Representative diagrams from 10 independent experiments are shown.