PMA/Io-induced iNKT functional responses. PBMC were stimulated for 6 hours with 25 ng/mL PMA and 500 ng/mL Io, and iNKT (A) IFNγ production and (B) TNFα production were compared among study groups. (C) Comparison of IFNγ production by LAG-3+ and LAG-3- iNKTs among all participants. Statistical comparisons made by Kruskal-Wallis (with Mann–Whitney post-test), Wilcoxon test and Spearman correlation. *p < 0.05, ***p < 0.001.