CCR6 and tuberculosis: Other Trm-like clusters of note include cluster 11 — CD69+ cells that coexpress PD-1, TIGIT, CXCR5, and ICOS, consistent with the phenotypic description of lung-resident T follicular helper cells (38) that were shown to be important in the mouse model of TB (39) — and cluster 16 — CD69+ cells that coexpress CCR6 and CCR4, classical markers of Th17 cells (40), and CD161 and CD39, novel Th17 markers (41, 42).