IL17A and sarcoidosis: Furusawa et al. [40] reported significant differences in the Th1/Th17 responses of peripheral blood mononuclear cells between sarcoidosis and control groups when stimulated with viable P. acnes but not with viable MTC (bacillus Calmette–Guérin) or ESAT-6; the increased interleukin-2 and decreased interleukin-17 responses to P. acnes suggested an imbalance of Th1/Th17 immune responses to the commensal bacterium in sarcoidosis patients.