Flow cytometric analysis of peripheral blood iNKT cells from patients with hypomorphic RAG mutations. Mononuclear cells (PBMCs) from a healthy control (representative of 6 donors) (A) and 5 patients with hypomorphic mutations of the RAG genes (B) were analyzed for the presence of iNKT cells. Leukocytes were enumerated by gating on CD45⁺CD3⁺ cells. iNKT cells were identified using PBS57-loaded CD1d tetramers (right) using cells stained with unloaded CD1d tetramers as control (left).