Citrus comparison of Vα2.3+Vβ22− (Figure 5I) and Vα2.3+Vβ22+ (Figure 5J) clusters (24987 and 24983, respectively) revealed abundance of both populations to be significantly increased in LS compared to non-LS patients, but the distribution of receptors associated with cell activation and effector functions (CD127, CD28, CD161) and immune regulation (PD-1, CTLA-4, ICOS) molecules, respectively, to differ between the two Vα2.3+ clusters. This evidence concerns the gene PDCD1 and Leigh syndrome.