Tregs, Th1, Th17, and Th17.1 cells constituted 5.7% ± 0.7%, 4.0% ± 0.6%, 12.7% ± 2.6%, and 27.7% ± 3.1% of CD4+ T cells in the BALF of sarcoidosis patients, respectively (Figure 4A). Here, CD4 is linked to sarcoidosis.