IL9 and tuberculosis: We first demonstrate that TB antigens induce an expansion of IL-10 expressing Th1 (IL-10+, IFNγ+, T-bet+), Th2 (IL-10+, IL-4+, GATA-3+), Th9 (IL-10+, IL-9+, IL-4−), Th17 (IL-10+, IL-17+, IFNγ−), and natural and adaptive regulatory T cells [nTregs; IL-10+, CD4+, CD25+, Foxp3+ and aTregs; IL-10 single+, CD4+, CD25−, Foxp3−] in PTB and LTB individuals, with frequencies being significantly higher in the former.