For example, human MAIT cells in tuberculosis pleural effusions [15] and tonsils [17] have been shown to produce IL-21, a key cytokine in B-cell differentiation, proliferation, and class switching [59], although this has not been confirmed in mice, and we did not find any differences in mucosal IL-21 concentration between treatment groups in our OSP vaccination model (Supplementary Figure 4F-G). This evidence concerns the gene IL21 and tuberculosis.