CCR6 and Autoimmunity: Assessment of cytokine expression among Th17 populations in humans and in murine models of autoimmunity and persistent bacterial infection revealed that CCR6−CCR2+ Th17 cells align with previously described GM-CSF+/IFNγ+ pathogenic Th17 cells, while CCR6+CCR2+ Th17 cells resemble previously reported Th17 cells with a more limited pathogenic potential.